Rory McIlroy has always seemed to possess an older head on young shoulders.

Indeed, when the Northern Irishman burst onto the scene in 2009, his success belied his inexperience.

His first major title came at the 2011 U.S. Open, as he finished eight strokes clear of Jason Day at Congressional Country Club in Maryland. Three more followed in the space of three years; two at the US PGA Championship and one at The Open.

It has been eight years since McIlroy claimed a major honour, but heading to The Country Club in Brookline, Massachusetts, the 33-year-old's form is as strong as it has been since he lifted his second US PGA title in 2014.

And in recent months, McIlroy has been seen as one of the voices of reason amid the emergence of the LIV Golf Invitational, which started in London last week.

Charl Schwartzel won the inaugural event of the Saudi Arabia-backed breakaway competition, which has drawn the likes of Phil Mickelson, Sergio Garcia, Dustin Johnson and Bryson DeChambeau.

"If it keeps going the way it's going, it's going to fracture the game – sorry, it's going to fracture the game more than it already is," McIlroy, desperate to focus on his own game this week, told Sky Sports on Tuesday.

"The professional world in golf has already been fractured, there's so many different tours, so many different things to follow, and I've always been an advocate of trying to make it more cohesive and try to get people to work together more. This is ripping that apart.

"It's certainly a burden I don't need. But I have pretty strong views on the subject and I don't think it would be right for me to have these strong opinions and not share them."

Perhaps what golf needs more than ever right now is a unifying force that both players and fans can get behind. McIlroy might present just that.

Rory reinvigorated

It has been a brilliant year so far for McIlroy. According to official PGA Tour statistics, he ranks first for scoring average (68.842), top for strokes gained: tee-to-green (1.888) and strokes gained total (2.282), while he also comes in third for driving distance (319.1 metres) and strokes gained off-the-tee (.913) so far this season.

That form has resulted in six top-10 finishes, including his second place at the Masters in April, which came courtesy of a bogey free 64 in the final round, and his victory at the Canadian Open last week.

Defending his Canadian Open crown will have given McIlroy a timely boost heading to Massachusetts, following on from his eighth place at the US PGA Championship last month. He is in fine fettle, but needs to overcome his major hoodoo...

Getting over the line

Four major titles in the space of four years seemed to have paved the way for McIlroy to go on and join the true greats of golf, but it has not quite been that way.

Since winning the U.S. Open in 2011, McIlroy has failed to make the cut on four occasions at this major, though has recorded top-10 finishes in each of the last three editions of the tournament.

His best result at any of the majors since 2014 came at Augusta earlier this year, but as we have seen in other tournaments on the circuit, McIlroy has been known to squander strong positions, and he might even prefer to be in the chasing pack come Sunday.

In January 2021, McIlroy held the 54-hole lead at the Abu Dhabi Championship, but a final-round 72 saw him finish third. He finished five shots back from the winner and it was a similar story at the DP World Tour Championship in December, when he missed the chance to become the first player to win the event for a third time, giving up a last-day lead to finish five behind Collin Morikawa. 

Composure will be key for McIlroy this time around, should he be in contention.

A date with fate?

It might just be a coincidence, but fate is a funny old thing, and Sunday will mark 11 years to the day since McIlroy won his first major, when he claimed the U.S. Open so convincingly.

Another iron in McIlroy's fire could be that his win at the Canadian Open moved him onto 21 PGA Tour titles, edging him ahead of LIV Golf chief executive Greg Norman. Going on to seal his second U.S. Open triumph, 11 years since he claimed his first, would be a fitting way for McIlroy to prove he is on the right side of this particular divide.

Now, he just has to go out and perform.

The season's third major begins on Thursday in Brookline, Massachusetts as the U.S. Open gets under way at The Country Club.

There will be a strange feeling at the tournament with it being the first major since the controversial LIV Golf International Series began.

The USGA has confirmed that players involved in the Saudi-backed breakaway who qualified for the U.S. Open will still be allowed to compete, despite the PGA Tour taking a harder stance and suspending those who played in last week's inaugural LIV Golf event in London.

That means the likes of Phil Mickelson, Dustin Johnson and Sergio Garcia will be present in Brookline.

Tiger Woods will not participate due to fitness concerns, but there are plenty of other potential candidates to go for victory at The Country Club, such as world number one Scottie Scheffler and defending champion Jon Rahm.

Stats Perform's experts have taken a look at who they believe could succeed.

RORY'S THE STORY AND HE'S PRIMED FOR MORE GLORY – Russell Greaves

Rory McIlroy has set the standards on and off the course in recent weeks, his win at the Canadian Open coming after he had pledged his allegiance to the PGA Tour in the midst of the inaugural LIV Golf event. That was the Northern Irishman's 21st PGA Tour title, fittingly edging him ahead of LIV Golf CEO Greg Norman, a fact McIlroy himself was quick to point out. In Massachusetts, McIlroy can distinguish himself even further from the likes of two-time major winner Norman as he seeks a fifth such title and second at this event. With accuracy off the tee likely to yield a premium on this course, McIlroy has the game to match his momentum and will doubtless be well backed by punters and fans alike. Sunday also marks 11 years to the day since McIlroy won the U.S. Open, collecting his first major success in the process.

DJ READY TO PLAY THE VILLAIN – Ben Spratt

Sure, Rory's return to the winners' circle at a major would be great, but that story surely pales next to the possibility of one of the LIV Golf rebels swooping in and taking the title. Johnson likely remains the breakaway league's best bet. Of course, he would not be a popular winner in front of a presumably vociferous Boston crowd, and the form book is not in his favour either, but Johnson has the talent to spoil the party; a U.S. Open victory in 2016 was the third of three straight top-five finishes – and it was only 18 months ago he was dominating the Masters. The 37-year-old has not won any event this year, in what stands as a career first, but this would be some time to end that drought.

RAHM READY TO MAKE HISTORY AFTER PLEDGING PGA LOYALTY – Patric Ridge

"I've never really played the game of golf for monetary reasons. I play for the love of the game, and I want to play against the best in the world. I've always been interested in history and legacy, and right now the PGA Tour has that." Those were the words of world number two Rahm, who is out to defend his title this week. Rahm finished T23 on his first appearance at the U.S. Open as a low amateur back in 2016, before he failed to make the cut in the next two years. However, he was tied for third in 2019 and T23 in 2020 prior to clinching his first major crown last year, finishing with two birdies on the final two holes to become the first Spanish golfer to win the major. The 27-year-old ranks first on the PGA Tour for shots gained off-the-tee, and although he struggled at the US PGA Championship, he has the opportunity to make history and create the legacy he dreams of in Massachusetts.

ROSE CAN BE A THORN IN RIVALS' SIDE – Peter Hanson

On the face of it, tipping a player ranked 48th in the world without a win to his name since January 2019 (Farmers Insurance Open) looks a little right field. At the time of that triumph, Justin Rose was world number one, but it has been a pretty mixed bag since then. Momentum is king in golf, though, and the Englishman scored a tie for fourth at the Canadian Open last weekend after shooting a sensational 10-under-par 60 in round four. Moreover, to win a U.S. Open you have to fight and scramble for a good score – qualities Rose, the 2013 champion, certainly possesses.

THOMAS HAS THE ENGINE NOT TO TANK – David Segar

Having won the PGA Championship at Southern Hills Country Club in May, Justin Thomas comes into this full of confidence and with good reason. He showed incredible fight to edge victory against Will Zalatoris in a play-off in Tulsa, having trailed by eight shots with 10 holes to play in the final round. Ranked fifth in the world, Thomas has always had the talent but, like many, it was always a question of putting it all together when the majors came around. With the experience of doing so fresh in his mind, and showing good form with third place at the Canadian Open, Thomas could pull off the rare feat of back-to-back major wins.

Jon Rahm says he is unsurprised by the amount of big-name golfers participating in the LIV Golf series given the financial rewards on offer, but sees more "meaning" in competing for historic prizes on the PGA Tour.

The Saudi-backed LIV Golf series, which held its first event in London last weekend with victor Charl Schwartzel pocketing $4.75million as the inaugural winner, has attracted several the game's biggest names by offering eye-watering prize sums.

The likes of Bryson DeChambeau, Phil Mickelson, Dustin Johnson and Sergio Garcia are among those to have signed up to the new circuit, with players participating in the first LIV event having been suspended by the PGA Tour last week.

Other stars, including Rory McIlroy, have made their opposition to the new tour clear, with the four-time major winner claiming on Tuesday it will "fracture" the sport.

And while world number two Rahm respects other players' decisions to feature in the breakaway competition, he simply does not see the appeal.

Speaking ahead of the U.S. Open, defending champion Rahm explained that he sees more "meaning" in competing with the world's best players in historic competitions on the PGA Tour.

"I mean, hundreds of millions of dollars are a pretty good damn reason for people to decide and go, and I see a lot of comments that's regarding it, but the high majority of the population, if they offered you 100 million or more for the next four years, a lot of people would go, right?" he said. 

"I'm not surprised at the number of players that went. I do see the appeal that other people see towards LIV Golf.

"[But] to be honest, part of the format is not really appealing to me. I want to play against the best in the world in a format that's been going on for hundreds of years. 

"There's meaning when you win the Memorial Championship. There's meaning when you win Arnold Palmer's event at Bay Hill. There's a meaning when you win, [at] LA, Torrey, some of the historic venues. That to me matters a lot.

"My heart is with the PGA Tour. That's all I can say. It's not my business or my character to judge anybody who thinks otherwise."

Rahm also added that the financial rewards on offer on the new tour – headed up by chief executive Greg Norman – would not change his mind.

"Truth be told, I could retire right now with what I've made and live a very happy life and not play golf again," the 27-year-old said. 

"I've never really played the game of golf for monetary reasons. I play for the love of the game, and I want to play against the best in the world. I've always been interested in history and legacy, and right now the PGA Tour has that."

Rahm's compatriot Garcia, meanwhile, joined Johnson in resigning his membership of the PGA Tour last month.

While Rahm says Garcia's decision is none of his concern, he hopes the split will not impact players' chances of competing at the Ryder Cup.

"[It's] not my business," he added. "He has given golf, [the] European Tour and the PGA Tour 20, 25 years of his life. It's his decision. It's not my job to judge. 

"That's all I can say. I don't know what's going to happen. I think the one thing that keeps coming to me out of all this and what can happen… I hope the Ryder Cup doesn't suffer.

"Are they going to be able to play Ryder Cup or not, the players that went? In my mind, Sergio, even if he is not breaking 90, he's a no-brainer pick, right? So what's going to happen? 

"You have quite a few young Americans. Bryson went, somebody that's probably going to be on the team in the future. 

"I think a week like that is a true essence of the game. That's where we all love to play."

Rory McIlroy says the ongoing LIV Golf series saga will serve to "fracture" the sport and the four-time major winner feels many PGA Tour players viewed those joining the Saudi-backed circuit as "selfish". 

The LIV Golf series - headed up by chief executive Greg Norman - has faced immense criticism since it launched, with opponents labelling the new tour as an exercise in "sportswashing". 

That has not stopped several of the game's biggest stars signing up, however, with Bryson DeChambeau calling his own choice to feature on the circuit a "business decision" after joining the likes of Phil Mickelson, Dustin Johnson and Lee Westwood in competing. 

The first LIV Golf event took place last weekend in London, with South Africa's Charl Schwartzel pocketing $4.75million as the inaugural winner.

McIlroy has been one of the most open critics of the new series, appearing to taunt Norman after surpassing his tally of 20 PGA Tour victories with his 21st triumph on Sunday, the successful defence of his Canadian Open title.

Before conducting a press conference ahead of the U.S. Open – which begins on Thursday – McIlroy insisted the new venture was only going to widen divides within the sport. 

"If it keeps going the way it's going, it's going to fracture the game – sorry, it's going to fracture the game more than it already is," he told Sky Sports.

"The professional world in golf has already been fractured, there's so many different tours, so many different things to follow.

"I've always been an advocate of trying to make it more cohesive and trying to get people to work together more. This is ripping that apart. 

"If people want to spend money in the game - and it's not regardless of where that money comes from - I think, if the Saudis are hell-bent on spending money in golf, let's get it spent in a way that benefits the wider ecosystem.

"That's where I would like to see it going, but whether that happens or not remains to be seen."

While McIlroy was reluctant to label any player's decision to feature on the new circuit as a "betrayal", he said many of his peers on the PGA Tour did not look upon such choices kindly.

"Betrayal's a very strong word," he said. "It's disappointing, I think the players that have decided to stay on the PGA Tour maybe feel slighted in some way, or feel those guys have been selfish, because it's for personal gain.

"I think in any industry or business, we have to lift each other up and try to make it as best we can for everyone. 

"I think if those guys [the LIV Golf players] thought outside of themselves, they'd see this wasn't best for everyone, that's my point of view on it.

"Everyone has their own goals and their own ambitions and thoughts, and they have to do what they feel is right for themselves."

Having reluctantly emerged as one of the most heralded opponents of the new circuit, McIlroy feels defending the PGA Tour is the right thing to do, considering his strong views.

"It's certainly a burden I don't need," he added. "But I have pretty strong views on the subject, and I don't think it would be right for me to have these strong opinions and not share them.

"I think I'm providing the commentary for a different thought process that is shared by a lot of people, that's the thing.

"I'm put in front of a camera more than most and everyone's here for me all the time about this subject."

Phil Mickelson has expressed his "deepest of sympathy and empathy" for the families of the 9/11 victims amid continued criticism over his decision to join the LIV Golf Invitational Series.

The controversial eight-event Saudi-backed breakaway circuit, which got under way in London last week, has a prize fund of $250million that is bankrolled by Saudi Arabia's Public Investment Fund (PIF).

Mickelson and the other American players taking part in the series have been accused by a group representing victims' families and survivors of "sportswashing" – the practice of using sport to improve a tarnished reputation.

Terry Strada, the chair of the 9/11 Families United, said in a statement: "Whether it was the appeal of millions of dollars of hard cash, or just the opportunity to prosecute your professional grievances with the PGA, you have sold us out.

"This is a betrayal not only of us, but of all your countrymen."

Strada cited Saudi Arabia's prominent role in the terror attack 21 years ago, with Osama bin Laden and 15 of the 19 hijackers being Saudi nationals.

In another uncomfortable news conference on Monday ahead of this week's U.S. Open in Massachusetts, Mickelson was asked directly about Strada's comments.

"I would say to the Strada family, I would say to everyone that has lost loved ones, lost friends on 9/11 that I have deep, deep empathy for them. I can't emphasise that enough," he said.

"I have the deepest of sympathy and empathy for them."

Asked if he intended to respond privately to the letter, Mickelson repeated his earlier answer.

Mickelson and the others to have joined up for the series have also faced criticism from their colleagues, with Rory McIlroy – the winner of last week's Canadian Open – among the more vocal of those to speak out against the LIV Series.

"I certainly respect Rory," Mickelson said. "I thought what a great finish on Sunday and a great accomplishment. What a career he has had. I certainly respect him. I respect his ideas. I respect all the players that choose to stay on the PGA Tour.

"I certainly think extremely highly of many of the players on the PGA Tour and their right to their own decisions.

"I gave as much back to the PGA Tour and the game of golf that I could throughout my 30 years here, and through my accomplishments on the course I've earned a lifetime membership. I intend to keep that and then choose going forward which events to play and not."

Justin Thomas called it "sad" that LIV Golf continues to dominate the headlines in the lead-up to the U.S. Open.

LIV Golf's first event took place this past weekend, with South Africa's Charl Schwartzel pocketing $4.75million as the inaugural winner.

Made possible through Saudi Arabia's Public Investment Fund, the upstart tour has thrown exorbitant sums of money at PGA Tour players to poach them away, including Bryson DeChambeau and Dustin Johnson.

Speaking to the media after opting to not play in Monday's U.S. Open practice round, Thomas said the ubiquitous LIV Golf discussion during one of the great weeks on the golfing calendar was "sad".

"I grew up my entire life wanting to play the PGA Tour," he said. "Wanting to break records, make history, play Presidents Cups, play Ryder Cups.

"The fact that things like that could potentially get hurt because of some of the people that are leaving, and if more go, it's just sad. 

"It's really no other way to say it. It just makes me sad, because like I said, I've grown up my entire life wanting to do that, and I don't want to do anything else.

"The people that have gone, like I said, they have the decision that they're entitled to make. Not necessarily that I agree with it one way or the other, but everything has got a price, I guess."

He later added: "You can't go anywhere without somebody bringing it up.

"It's sad. This is the U.S. Open, and this is an unbelievable venue, a place with so much history, an unbelievable field, so many storylines, and yet that seems to be what all the questions are about.

"That's unfortunate. That's not right to the USGA. That's not right for the U.S. Open. That's not right for us players. But that's, unfortunately, where we're at right now."

Thomas was not done there, going on to discuss why he does not think the money is worth it, but also why it is not fair to make character assessments on the players who decided to make the move.

"There's no amount of money that you could get that [can make you happy doing something] you don't love or enjoy," he said. 

"You're still going to be miserable. You're still not going to enjoy it. Although you might be miserable in a bigger house or a nicer car, that doesn't necessarily mean that your life is going to be any better.

He added: "I'm the first to admit that there's times where people do something, and I bash them – obviously not externally – maybe internally with friends or whatever it is. It's not necessary.

"You can disagree with the decision. You can maybe wish that they did something differently… being in the media as a writer, you have to write about it. I understand that. 

"But for people at home to necessarily say that Dustin Johnson is now a bad person, that's not fair. That's just not right.

"Now, again, I said it last week, I'll say it again, do I wish he wouldn't have done it, and am I a little sad about it? Yeah – but it is what it is."

PGA Tour commissioner Jay Monahan described the LIV Golf Invitational as a "series of exhibition matches" while defending his decision to suspend players who defected to the breakaway series.

Charl Schwartzel, who won the inaugural LIV event near London this weekend, has been suspended from the PGA Tour along with the likes of Dustin Johnson, Phil Mickelson and Sergio Garcia for their involvement in the series.

The LIV series is set to hold eight 54-hole, no-cut tournaments with 48-man fields this year, with players not only earning significantly higher prize money, but taking substantial sign-on fees. Bryson DeChambeau and Patrick Reed have been the latest to defect.

Asked why golfers cannot compete on both tours, Monahan took an assertive stance.

"Why do they need us so badly? Those players have chosen to sign multi-year, lucrative contracts to play in a series of exhibition matches against the same players over and over again," he said on CBS' broadcast of the Canadian Open.

"You look at that versus what we see here today, and that's why they need us so badly.

"You've got true, pure competition, the best players in the world here at the RBC Canadian Open, with millions of fans watching. And in this game, it's true and pure competition that creates the profiles and presences of the world's greatest players."

Monahan was particularly critical of LIV's source of investment, with the Public Investment Fund in Saudi Arabia which has been accused of sports washing and using the tour to take attention away from a history of human rights abuses.

He also said players who defected would "have to be living under a rock" to not consider that context, but chose instead to relate the significant outlay to sign players and hold events to the potential return on investment.

"It’s not an issue for me, because I don’t work for the Saudi Arabian government," Monahan said. "But it probably is an issue for players who chose to go and take that money. I think you have to ask yourself the question, why?

"Why is this group spending so much money — billions of dollars — recruiting players and chasing a concept with no possibility of a return? At the same time, there’s been a lot of questions, a lot of comments, about the growth of the game. And I ask, how is this good for the game?

"I would ask any player that has left, or any player that would consider leaving, have you ever had to apologise for being a member of the PGA Tour?"

Rory McIlroy saved his best for last to defend his Canadian Open title on Sunday and could not resist a sly dig at LIV Golf chief executive Greg Norman afterwards.

At the end of a chaotic week for the sport, with the controversial Saudi-backed LIV Golf Invitational Series commencing in competition with the PGA Tour, McIlroy posted his best round of the tournament at St. George's with an eight-under 62.

Playing in the final group with Tony Finau and Justin Thomas, the 33-year-old finished on 19-under for the tournament in front of a packed gallery and secured his 21st PGA Tour win, moving him ahead of Norman's 20.

Though evidently happy he secured the win heading into the U.S. Open, as one of the more vocal critics of LIV Golf, the world number eight made sure everyone knew he was aware he had overtaken Norman.

"Twenty-first PGA Tour win. One more than someone else," he told CBS. "That gave me a little bit of extra incentive today. Happy to get it done.

"It's incredible. Playing with Tony [Finau] and JT [Thomas], two of the top players in the world, and all of us playing the way we did, the worst score in the group was six-under par.

"This is a day I'll remember for a long, long time. I've sort of rededicated myself to the game a little bit, sort of realised what made me happy and this makes me happy."

McIlroy led the entire way on Sunday, starting the final round in a share of the lead with Finau.

He started fast, too, making five birdies on the front nine before commencing the back nine with another three on the bounce.

Bogeys on the 13th and 16th holes opened the door for Thomas and Finau but it was promptly shut, with the Northern Irishman closing out the round with another pair of birdies.

Finau and Thomas finished outright second and third on 17- and 15-under respectively, while Justin Rose tied Sam Burns on 14-under after bogeying the 18th to just miss out on a spectacular sub-60 score.

Tony Finau birdied the final hole for an eight-under 62 on Saturday to share the lead with Rory McIlroy, coming into the final round of the Canadian Open.

Finau had the best round of the tournament so far, scoring an eagle on the par-five ninth before making four birdies on the back nine.

The 32-year-old is looking for only his third PGA Tour victory, with his last win coming in a playoff over Cameron Smith in last year's Northern Trust.

McIlroy had a tricky uphill putt to also birdie on the 18th hole, despite an exceptional approach to set it up, but he had to ultimately two-putt to finish the round after his birdie attempt skimmed over the edge of the cup.

The 33-year-old has been in confident touch at St. George's this week and continued that on Saturday, posting a five-under 65 with assertive driving and wedge-play.

After a bogey on the par-three eighth, the Northern Irishman responded with three birdies over the next four holes, before managing another birdie on the par-five 15th.

The final hole would have been an apt punctuation mark for his third round, after scores of 66 and 68 over the opening two days.

McIlroy has had to wait three years to defend his 2019 title, with the Covid-19 pandemic forcing a cancellation of the tournament in 2020 and 2021.

He is among five players ranked in the world's top ten in a high-profile field at Toronto, coming into next weekend's U.S. Open, with Justin Thomas and Sam Burns joined by Wyndham Clark and Alex Smalley on nine-under.

Cameron Smith has recovered from an opening-round six-over 76 to finish on one-under after 54 holes, posting a 68 on Saturday, while world number one Scottie Scheffler scored a disappointing 71.

Patrick Reed has joined the LIV Golf Invitational Series and become the latest high-profile name to turn their back on the PGA Tour. 

It was confirmed on Saturday that the 2018 Masters champion had signed up for the Saudi Arabia-backed circuit, which was this week joined by Bryson DeChambeau and had Phil Mickelson and Dustin Johnson contesting its inaugural event this weekend. 

Reed is set to make his first appearance when the series travels to Portland for the second of its eight events later this month. 

LIV Golf CEO and commissioner Greg Norman said: "The growing roster of LIV Golf players gets even stronger today with a player of Patrick Reed's calibre. 

"He has a proven track record as one of the most consistent competitors in pro golf and adds yet another big presence at our tournaments. 

"He's a major champion who has had a significant impact playing international team competitions, and he'll bring another impressive dynamic to our team-based format at LIV Golf." 

Reed has slipped to 36th in the world rankings having only made his first top-10 finish of 2022 at the Charles Schwab Challenge in May. 

He will now be ineligible for any tournaments on the PGA Tour after it was this week confirmed all players competing at any LIV Golf events would be indefinitely suspended. 

However, Rickie Fowler and Bubba Watson are among another group of players reportedly set to make the switch to LIV Golf, which now boasts a field that includes nine major champions. 

Wyndham Clark was able to hold onto his outright lead at the Canadian Open with an even par second round on Friday, one stroke ahead of Rory McIlroy and the chasing field.

Clark remains at seven under after a spectacular 63 on Thursday, posting three birdies and three bogeys on his second trip around the course.

McIlroy headlines the five-man group at six under, along with American trio Keith Mitchell, Jim Knous and Alex Smalley, as well as England's Matt Fitzpatrick, who closed his round with three consecutive bogeys to surrender the lead.

Alone at five under in outright seventh is Austin Cook, who posted Friday's round of the day with his six-under 64, going bogey-free with six birdies to vault himself into contention after entering play at one over.

Scottie Scheffler and Sam Burns are in a logjam at four under, as is Shane Lowry, while Tony Finau and Harold Varner III are one further back at three under, rounding out the top-20.

Justin Thomas shot his second consecutive 69 to head into the weekend at two under, while English trio Danny Willett, Justin Rose and Aaron Rai sit at one under.

The second-best score of the round belonged to Cameron Smith, who shot a 65 to land right on the cut-line after a calamitous 76 in his opener.

Rory Sabbatini and Stuart McDonald missed the cut by one stroke, while Camilo Villegas was a further shot back after going five over on his last four holes.

Bryson DeChambeau has become the latest high-profile player to shun the PGA Tour and join the Saudi-backed LIV Golf Invitational Series.

The 2020 US Open winner, who has eight PGA Tour titles to his name in total, joins the likes of Phil Mickelson and Dustin Johnson in switching to the rival circuit.

DeChambeau's involvement was made official on Friday by LIV Golf, which launched with its first event on the outskirts of London on Thursday.

His first appearance will be in the second of the eight-series event in Portland later this month.

LIV Golf chief executive Greg Norman said in a statement: "Bryson DeChambeau is an exciting addition to LIV Golf's supercharged style of play. 

"He is passionate about the sport, innovative in his approach and committed to pushing the boundaries in pursuit of excellence.

"He's not afraid to think outside the box and supports our mission of doing things differently to grow our game.

"The power and energy he brings to the course will deliver added electricity to our competition in Portland and beyond."

DeChambeau is currently 28th in the world rankings after slipping out of the top 10, where he had spent most of the past two years, due to a niggling injury issue.

The American missed the cut at last week's Memorial Tournament and will now be blocked from competing in any further PGA Tour events, likely including next week's U.S. Open.

That comes after the Tour confirmed on Thursday that all players competing in the opening event this week, and any who play in future events, are indefinitely suspended.

DeChambeau is the eighth major champion to defect to LIV Golf, along with Sergio Garcia, Johnson, Mickelson, Martin Kaymer, Graeme McDowell, Louis Oosthuizen and Charl Schwartzel.

Wyndham Clark leads the Canadian Open after the first round of play, shooting a seven-under 63 in Toronto on Thursday.

Amid an awkward atmosphere around the course with LIV Golf's commencement outside London on Thursday and suspension for players part of the rebel tour, Clark was able to hold his lead against the afternoon wave of players.

After securing a berth at next weekend's U.S. Open in a qualifier on Monday, the 28-year-old carried some confidence into the opening day at St. George's Golf and Country Club, starting with five birdies on the opening nine.

He went bogey-free on the closing nine holes, scoring birdies on the par-four fourth and seventh holes.

Ian Poulter and Graeme McDowell have hit out at the PGA Tour for their handling of players who have decided to participate in LIV Golf, calling it a "power struggle".

The PGA Tour made the bold move of waiting until after the first LIV Golf event in London had teed off before announcing that any player who participates in the Saudi-backed promotion is "suspended or otherwise no longer eligible to participate in PGA Tour tournament play, including the President's Cup."

In the first round of LIV Golf's debut event, Charl Schwartzel earned the outright lead at five under, trailed by Hennie Du Plessis at four under, while Dustin Johnson and Phil Mickelson were also among the 10 players to finish under par.

Speaking after the round, Poulter strongly disagreed with the PGA Tour's decision to force players to choose between the tours.

"I've played a lot of tournaments all around the world, this event is no different," he said. "It's a shame if they view this as something different.

"I will appeal for sure. It makes no sense. Having two tour cards and the ability to play golf all over the world, what's wrong with that? I believe I've been given permission in the past to play in events around the world.

"I don't know why [the decision was made] – we can all make assumptions as to why. Competition is probably the real reason. It's a power struggle, and it's just disappointing."

Fellow U.K. golfer McDowell echoed Poulter's sentiments, saying it is ridiculous that they are not allowed to compete in events relatively local to them.

"Some guys believe that they shouldn't be in the situation where they have to resign," he said. "They don't feel like they are doing anything wrong. 

"We haven't been issued releases, [but] we feel like we should have been issued releases. We've done it for the last 20 years, operated all over the world.

"We're in the U.K – you've players like myself and Ian Poulter and Lee Westwood, we are in our home markets here.

"We should be allowed to operate here as professional golfers. But hey, we all know the situation is about something bigger.

"It's competition and it's not liked. They are having to play the game the way they feel they have to play it, which is playing hard ball.

"We feel confident that we are well-protected and we are going to just try and do our best."

Rory McIlroy and Justin Thomas have supported the PGA Tour's decision to suspend all players competing in the LIV Golf Invitational Series.

PGA Tour commissioner Jay Monahan sent a memo to all members on Thursday confirming the news, shortly after LIV Golf's first event had launched at Centurion Club near London.

All 17 Tour members competing in the first Saudi-backed tournament of the breakaway series, including six-time major winner Phil Mickelson, were informed they are no longer eligible to play in events on the circuit.

The memo warned that any player featuring in future LIV events will face a similar punishment.

McIlroy said on Wednesday he understands why some have made the switch due to the huge sums of money on offer, but the Northern Irishman is pleased with the decision to block players from competing on both circuits.

"I think at this point, Jay [Monahan] has been pretty transparent in terms of he's just going to act within the tournament regulations and the rules that are set for a PGA Tour member," McIlroy said.

"All he's doing is basically going by the book. I think that the majority of the membership that are here this week and that haven't gone and played elsewhere really appreciate that.

"So, I think he's done the right thing because these guys have broken rules and done things outside of the tournament regulations, and because of that, there are going to be consequences, I guess."

McIlroy was speaking after carding an opening-round 66 at the RBC Canadian Open on Thursday, with Thomas three shots further back.

While the four-time major winner is against the idea of the breakaway series, he will be tuning in out of curiosity.

"I think like everyone else, I'm intrigued and I'm a fan of golf," McIlroy said. "I've got quite a few guys over there that I call friends that are playing. 

"Yeah, of course I'll see it and watch it and see what all the fuss is about."

Mickelson is the highest-profile casualty of Thursday's announcement, with Dustin Johnson and Sergio Garcia having already notified the Tour that they have resigned their membership.

Louis Oosthuizen, Lee Westwood and Ian Poulter are among the other notable names featuring at the three-day LIV Golf Invitational London event that will have 12 teams and 48 players.

Echoing the comments made by McIlroy, Thomas said: "I'm pleased. I think anybody that's shocked clearly hasn't been listening to the message that Jay and everybody's been putting out. They took that risk going into it, whether they thought it was a risk or not.

"Like I've said the whole time, I have great belief and great confidence in the PGA Tour and where we're going and continuing to grow to, and those guys just aren't going to be a part of it.

"[LIV Golf] are obviously throwing so much money at people that it's very hard to turn down. I don't care what you say in terms of that people play for different reasons. It doesn't matter who you are or what it is, everything has a number.

"They're reaching that number for some people, and I hope that they don't get others. But I think a very strong core group of us is very stable and firm in our position, and I hope that it stays that way."