Roger Federer says he hopes to return to action by the end of the summer, with his recovery from knee surgery likely to rule the 20-time grand slam winner out of Wimbledon.

The 40-year-old underwent surgery on his right knee for the third time last August, and has missed five of the last seven grand slams.

Federer made the quarter-finals at Wimbledon last year, but coach Severin Luthi recently said that he "can't imagine" the eight-time Wimbledon winner featuring in London this summer.

Federer has now provided an update on his recovery to Swiss broadcaster SRF, saying that the end of summer or start of autumn is a realistic target for his return, which could mean he is back for the US Open that starts on August 29.

However, he feels "positive" about his return to the court whenever that comes.

"It will certainly be a while," Federer said. "The end of the summer, early autumn, [that's] where I'm aiming for a comeback.

"It's [the knee] fine. Much better. Obviously, I was on crutches for two months, so you have to start from the bottom.

"It [the surgery] was certainly the right thing to do, the knee wasn't right after Wimbledon [last year], so it couldn't go on.

"Currently I'm in three parts. First, the whole rehab, getting back on your feet at the beginning. Then afterwards, learning to walk and building up the whole thing.

"It's only now where I'm at the phase where I can start thinking about my comeback. I had a very good MRI a few weeks ago, which makes me feel very positive."

Federer's tally of 20 career Grand Slam titles was surpassed by Rafael Nadal in January's Australian Open, and the duo are set, fitness permitting, to team up to represent Europe in the Laver Cup, which takes place in September.

The timeline for Federer's recovery also means that he will miss the second slam of 2022, May's French Open at Rolland Garros.

Nikita Mazepin said he was "very disappointed" after Haas sacked him from their driver line-up and cut lucrative ties with Russian backer Uralkali.

Russian racer Mazepin was consistently a backmarker during the 2021 season, his first year on the F1 grid, and was frequently outperformed by team-mate Mick Schumacher.

It has been Russia's invasion of Ukraine that has cost him his seat for 2022, however, rather than his results on the track.

Mazepin's father, Dmitry, has close ties to Vladimir Putin, holding face-to-face business talks with the Russian president as recently as January. Dmitry Mazepin is deputy chairman of Uralkali, the potash producer that has been a major financial backer of Haas.

As well as ousting 23-year-old Mazepin, Haas announced the commercial link with Uralkali has also been scrapped with immediate effect.

Haas removed the Uralkali logos from their cars for the final day of pre-season testing in Barcelona last month, in keeping with wider efforts to impose sporting sanctions on Russia.

The Russian Grand Prix for 2022 has been cancelled, with F1 announcing this week it has terminated its deal for future races in the country.

Mazepin responded to news of his dismissal by Haas on Saturday, stating: "I am very disappointed to hear that my F1 contract has been terminated.

"While I understand the difficulties, the ruling from FIA plus my ongoing willingness to accept the conditions proposed in order to continue were completely ignored and no process was followed in this unilateral step."

He did not clarify further on those points, but said he would elaborate on his statement "in the coming days".

"To those who have tried to understand, my eternal thanks," Mazepin added. "I have treasured my time in F1 and genuinely hope we can all be together again in better times."

Before Haas announced their decision, it had already been revealed that Mazepin would be banned from competing at the British Grand Prix.

J.B. Bickerstaff worked with James Harden while the duo were with the Houston Rockets, and the Cleveland Cavaliers coach continues to be impressed by the Philadelphia 76ers man.

Harden registered 25 points, 11 assists and three rebounds as the in-form Sixers won a fifth straight game on Friday, beating the Cavs 125-119.

While Joel Embiid failed to hit his usual high marks, scoring 22 points, Tyrese Maxey stepped up with 33 points, including five threes.

Harden added two three-pointers to the 76ers tally, moving onto 2,559 for his career, meaning he only needs one more to match Reggie Miller for third on the all-time list (regular season only).

"He sees the game a step ahead," Bickerstaff told reporters when asked about Harden.

"He's not one of those guys that's just going so fast he's waiting for the offense to react.

"He's forcing the defense to react. He's one of the most creative decision-makers and passers in our game. He also knows when to make the play that's right in front of him."

Reflecting on his team's display, Bickerstaff – who was fined $20,000 after being ejected from the game during Monday's defeat to the Charlotte Hornets – was satisfied despite a third-straight loss.

"We felt and looked like ourselves for the first time in a while," he said. "We just happened to run into a really good basketball team."

Harden finished with at least 20 points and 10 assists for a third game in four, yet the former Brooklyn Nets shooting guard was not thrilled with his own display.

"I've got to do a better job of being more solid, I've got to be smarter so I can be out there and help my team," he told reporters.

Yet Maxey stepped up regardless, and Harden was impressed.

"On any given night, it can be any one of us to go off," Harden said of his team-mate. "Tyrese really picked it up for us tonight." Coach Doc Rivers, meanwhile, labelled Maxey "a fearless kid".

Giannis Antetokounmpo and Jrue Holiday called for reigning NBA champions the Milwaukee Bucks to keep improving after they battled past the Chicago Bulls.

The Bucks edged out the Bulls 118-112, with Holiday finishing on 26 points, while Giannis Antetokounmpo had 34 points and 16 rebounds as Milwaukee made it three wins on the spin.

It was not all straightforward for Mike Budenholzer's side, though, given they went from leading by 14 in the second quarter to trail by seven through the third.

However, Holiday delivered 15 points in the fourth quarter as the Bucks rallied to another victory, just as they did at the Miami Heat to triumph by one on Wednesday.

"It's just a feeling and you know you've got to turn it on," Holiday said.

"It's time for us to lock-in. It's time for us to just concentrate, be aggressive and make good plays, smart plays, down the stretch."

The Bucks are now tied with Chicago for the Central Division lead, both sat on 39-25, with Milwaukee next hosting the NBA-leading Phoenix Suns on Sunday, with the Bulls going up against the Philadelphia 76ers a day later.

"We got to keep it up," Antetokounmpo said. "If good things are going on, you got to keep waking up the next day and keep learning something new, keep evolving, keep improving."

Milwaukee did well to limit a star-studded Bulls line-up. Zach LaVine headed the Chicago scoring with 30 points, while DeMar DeRozan managed 29 but finished 11 for 30 from the field.

DeRozan believes Milwaukee displayed their championship credentials.

"I felt like we competed," he told reporters. "It came down to the last couple minutes. They're defending champs for a reason."

Formula One team Haas have cancelled the contract of Russian driver Nikita Mazepin amid the Ukraine crisis.

Mazepin's father, Dmitry, has close ties to Vladimir Putin, holding face-to-face business talks with the Russian President as recently as January.

Dmitry Mazepin is deputy chairman of Uralkali, the potash producer that has been a major financial backer of Haas.

As well as ousting 23-year-old Mazepin, who was the only Russian with an F1 drive for the 2022 season, the commercial tie-up with Uralkali has also been scrapped.

It comes as Russia's invasion of Ukraine continues. Thousands have reportedly been killed since the start of the attack on February 24, including many civilians.

Haas said in a statement on Saturday: "Haas F1 team has elected to terminate, with immediate effect, the title partnership of Uralkali, and the driver contract of Nikita Mazepin.

"As with the rest of the Formula 1 community, the team is shocked and saddened by the invasion of Ukraine and wishes for a swift and peaceful end to the conflict."

Haas removed the Uralkali logos from its cars for the final day of pre-season testing in Barcelona last month.

The team's other driver is Mick Schumacher, son of German great Michael Schumacher. Haas have yet to announce who will replace Mazepin in the new season, which gets under way in Bahrain in two weeks' time.

The Russian Grand Prix for 2022 has been cancelled, with F1 announcing this week it has terminated its deal for future races in the country.

Elina Svitolina saw her hopes of delivering an emotional title for Ukraine ended by Camila Osorio in a tough quarter-final loss at the Monterrey Open.

Top seed Svitolina wore the yellow and blue colours of her home country, which has come under attack from Russia's military in the past fortnight.

However, the former world number three could not capitalise on a fast start, or a big lead in the deciding set, as she slipped to a 1-6 7-5 7-6 (7-5) defeat in two hours and 33 minutes.

Svitolina held a 4-1 lead in the third set, but 20-year-old Colombian Osorio recovered the double break to edge out the 2020 champion, sealing the win in a deciding tie-break.

That was the third tight three-set battle of the day, with Brazil's Beatriz Haddad Maia earlier scoring a 4-6 6-4 7-6 (9-7) win over Marie Bouzkova, and Nuria Parrizas Diaz achieving a 6-3 1-6 6-4 victory in an all-Spanish clash with Sara Sorribes Tormo.

Parrizas Dias will face Osorio in Saturday's semi-finals, while Haddad Maia faces a tussle with US Open runner-up Leylah Fernandez, who was a late-night 7-6 (7-4) 6-4 winner against China's Wang Qiang.

Reigning NBA champions the Milwaukee Bucks claimed another big win on Friday as they toppled the Chicago Bulls 118-112.

Jrue Holiday came up big down the stretch to finish on 26 points, while Giannis Antetokounmpo had 34 points and 16 rebounds as the Bucks made it three wins on the spin.

While the Bucks are regaining form at the right time, the Bulls have now lost four on the bounce, though they hold an identical 39-25 record to Milwaukee.

Holiday hit the game-winning layup with less than two seconds left in the Bucks' win over the Miami Heat on Wednesday and he scored 15 points in the final quarter to help ensure the Bucks' 14th win against the Bulls in their last 15 meetings.

DeMar DeRozan has 29 points but was kept well contained overall, with Zach LaVine top scoring for Chicago with 30.

It was far from plain sailing for the Bucks, however, with Chicago having overturned an initial 14-point deficit to lead by seven after the third quarter.

Suns edge out Knicks as Randle's temper flares 

Next up on the Bucks' tough run are the NBA-leading Phoenix Suns, who scraped onto 51 wins for the season with a 115-114 triumph over the New York Knicks.

Cameron Johnson hit a buzzer-beating three-pointer to snag a comeback victory and finish with a career-high 38 points in the process.

The Suns, without Chris Paul and Devin Booker, looked set to lose out with the Knicks leading by 14 in the third quarter, only for Julius Randle to be ejected after a confrontation with Johnson.

Sixers make it five in a row

The Philadelphia 76ers reeled off a fifth straight win as they dispatched the Cleveland Cavaliers 125-119.

James Harden had 25 points and 11 rebounds to continue his strong start, while Joel Embiid got a relatively low, by his standards, 22 points on the board. That was no matter for Philadelphia, though, as Tyrese Maxey scored 33 points, with his haul including five three-pointers.

The Utah Jazz had a shocker as they went down 124-90 to the New Orleans Pelicans, Shai Gilgeous-Alexander's 33 points was not enough as the Oklahoma City Thunder lost to the Minnesota Timberwolves, and there were victories for the Houston Rockets, the Atlanta Hawks, the Detroit Pistons and the Orlando Magic.

Former Ukrainian tennis player Sergiy Stakhovsky is "pretty sure" he is on a Russian army target list after leaving his family to take up arms in defence of his country.

Stakhovsky, 36, recently returned to Kyiv to be part of the armed resistance following Russia's invasion of Ukraine.

The attack started last Thursday and it has continued since, with Ukrainian civilians subsequently arming themselves to fight for their country.

Stakhovsky has been especially active with media duties in the past few days, and as such he believes himself to be a marked man for speaking out against Vladimir Putin and Russia.

But the 36-year-old said he has been driven by a moral compass to fight the Russian forces despite having no formal military training.

He told Stats Perform: "You have to be scared. I mean, if you don't [get] scared then you're stupid, I guess. Then of course, you need to calculate all the circumstances and everything that could come out of it.

"I mean, I'm pretty sure that I'm on a nice list of the Russian army to, not be really – let's say – treated well. But it is what it is.

"Russia is a dictatorship state. If you show resistance, if you show that you don't agree with what they do, if you show that you don't want to have them here, they put you to the ground.

"They don't really argue with you. It's a state which is controlled by one man and the system is so rotten that it just eats up everybody who is not willing, who is actually expressing a different mind.

"So of course, it is scary, it is unpleasant. But... I can be scared in any part of the world. It's not going to change anything."

Stakhovsky, a father of three, felt he had an obligation to return to Kyiv to fight rather than stay with his family.

But he accepts there is only so much Ukrainians can do with the love, prayers and support of the world, urging politicians to do more without selling Ukraine out, convinced surrender will doom many more for speaking out.

"I wouldn't want any father to make that choice [to fight] or to make the decision anytime, anywhere in the world," he continued. "It's something that you don't really want to do. It's not, there's no right choice.

"In this case, I have three kids, which I have to raise, and I have to look after and I want to enjoy them finally, after finishing my career. And instead of that I'm here in Kyiv with a gun and trying to prove a point that Russia is doing the wrong thing.

"Yes, I'm morally right, 100 per cent and all of Ukraine is right. Russia is at fault, but the whole world just seems not to… well, the people of the world they care. They care and they send their appreciation, their love and their prayers and their support, but it's not going to do justice.

"The politicians are the main players in this whole area, and if they don't step up, if they don't save lives – because after all, the most important part in all of it in life is life itself – if they have a chance to save everything starting from tomorrow, they should.

"But they should not on terms that [mean] we give up [in] Ukraine and we save lives [by surrendering], because that's killing lives because then after they surrender Ukraine, the Russian machine will find every single individual who was in the resistance, who was willing to fight, and they will kill him, or put him in prison, they will poison him, they would kill him, it doesn't matter how, but they will find a way to get rid of these people.

"And we're talking about more hundreds and thousands of people. Russia these days is a Soviet Union of the Stalin era. It's a machine which is killing people."

Viktor Hovland holds a two-shot lead at the half-way point of the Arnold Palmer Invitational after Rory McIlroy endured a disappointing finish.

Overnight leader McIlroy was not as sharp as he was on the opening day at Bay Hill but still looked in with a chance of retaining his status as pacesetter for much of the round.

That was until the 15th, when he needed three putts from 30 feet. He then missed a birdie opportunity on 16 and failed to save par from eight feet on 17.

The Northern Irishman ultimately finished at level par for the day with 72 – Hovland, who started on the 10th, carded 66, giving him the round of the day and the lead.

His score would have been even better had he not bogeyed the 13th, however he responded admirably to that set-back with three birdies in his next four holes.

Hovland added two more on the fourth and sixth to ultimately set the clubhouse lead as he moved to nine under for the tournament – McIlroy failed to rise to his challenge.

Joining McIlroy two shots back on seven under in a tie for second are Talor Gooch and Tyrrell Hatton, the latter of whom felt his four-under 68 was "pretty flattering".

Similarly, Hovland is not getting carried away with his position in the standings, particularly considering he was only two shots off the lead heading in the weekend last year and went on to finish 15 off the pace.

"I kind of try to forget the weekend here last year," Hovland told the PGA Tour. "I played really well the first few days, very similar to how I played so far this year.

"The course just gets harder and harder every single day, and it started blowing. A few too many bad swings and I ended up in bad spots and just didn't really take my medicine."

As for McIlroy, the four-time major champion was taken aback by how quickly conditions on the course changed from Thursday, adamant he will be better prepared on day three.

"Those are the sort of greens you expect to see late on a Sunday, not late on a Friday," McIlroy added. "It's going to be interesting to see where they go from here, but it's going to be a good test over the weekend.

"I'm glad I got 18 holes in those conditions because the course definitely changed a lot from when I played it yesterday morning to this afternoon. I'll be a little more prepared for it [on Saturday]."

Billy Horschel is one shot further back on six under, and then there's a three-shot gap to a group of seven – world number one Jon Rahm is at two under.

Patrick Reed, Henrik Stenson and Justin Rose were among those to miss the cut, which was set at three over par.

Phil Mickelson will skip the Players Championship as his hiatus from golf continues. 

Six-time major champion Mickelson was a notable absentee from the 144-player field that features 48 of the top 50 in the world rankings. 

The 51-year-old said in February he was taking some time away from the sport following the backlash to his comments promoting a Saudi Arabia-backed Super Golf League. 

Mickelson had suggested that although Saudi Arabia has "a horrible record on human rights", the threat of the potential breakaway competition could be used to "reshape how the PGA Tour operates". He subsequently apologised for making "reckless" comments. 

While Mickelson has yet to set a date for his return to action, it will not come at TPC Sawgrass next week. 

Harris English, Steve Stricker and Tiger Woods were the only other qualified players not to commit to the competition. 

Dayana Yastremska maintained her emotional run at the Lyon Open by beating fifth seed Jasmine Paolini in straight sets to book a semi-final spot. 

The Ukrainian wildcard secured her place in the last four on Friday with a 6-4 7-6 (7-3) victory over the Italian amid the war with Russia in her home country. 

The 21-year-old fled Odessa with her sister last week, separating from her parents in the process, and has spoken about her desire to honour those back in Ukraine with a title. 

She will face second seed Sorana Cirstea after the Romanian made short work of Anna Bondar with a 6-3 6-3 victory. 

Elsewhere, Caroline Garcia toppled another seed after fighting back to beat Alison van Uytvanck 4-6 6-3 7-5. The home favourite knocked out top seed Camila Giorgi in the first round and has a semi-final clash against Zhang Shuai to look forward to. 

Zhang did not have to sweat to make her place after Vitalia Diatchenko was forced to retire at three games down in the first set through injury. 

Major League Baseball's Players Association (MLBPA) announced on Friday it will set up a $1million fund to help employees affected by the labour dispute that has delayed the start of the 2022 season.

The support program, which will be overseen by the MLBPA in conjunction with the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO), is designed to provide financial assistance for stadium workers and other employees who may endure hardship by owners' lockout and cancellation of games.

"There are a lot of people who make our game great. Many aren't seen or heard, but they are vital to the entertainment experience of our games," MLBPA executive board leaders Andrew Miller and Max Scherzer said in a statement.

"Unfortunately, they will also be among those affected by the owner-imposed lockout and the cancellation of games. Through this fund, we want to let them know that they have our support."

MLB Commissioner Rob Manfred announced on Tuesday that the league has cancelled all games scheduled for the first week of the upcoming season due to the current impasse in negotiations for a new collective bargaining agreement. It's the first work stoppage since the players' strike in 1994-95 that wiped out the 1994 World Series.

The MLPA added that it will work with the AFL-CIO in the coming weeks to determine which areas will be most impacted by the stoppage and outline a plan to distribute its resources to where they will be most needed.

"Whether you're a worker on the baseball field, or a worker behind the scenes, we all deserve respect and dignity on the job," AFL-CIO president Liz Shuler said. "The labour movement will do everything in our power to support these and all workers."

The owners imposed the current lockout on Dec. 2 following the expiration of the previous CBA, and Manfred announced an agreement would need to be reached by Tuesday in order to prevent a delay to the season's start. The two sides met extensively in Florida earlier this week, but remain at odds on key economic elements to prevent a deal from being reached.

Talks broke off between the two parties following Tuesday's deadline, and no decision has yet been made as to when negotiations will resume.

INEOS Grenadiers rider Pavel Sivakov's request to compete for France rather than Russia has been approved by the UCI.

The 24-year-old last week stated that he is "totally against war" following Russia's invasion of Ukraine.

Sivakov revealed he had already wanted to become a French national before Vladimir Putin ordered Russian troops to invade Ukraine and cycling's world governing body has now sanctioned his switch.

"I was born in Italy and moved to France when I was one year old," Sivakov said. "France is where I grew up and was educated and where I fell in love with riding my bike which led me to racing. It feels like my home.

"I have wanted to become a French national for some time and had made the request to the UCI, but given what is happening in Ukraine at the moment, I wanted to fast-track this.

"I want to thank the UCI and the team at INEOS Grenadiers for supporting me with this process and helping make this a reality. To now have the opportunity to race as a French national in international events makes me incredibly happy.

"It would be a dream to race in Paris at the 2024 Olympics for France and this is something that the team have said they would fully support.

"As I have previously said, I am totally against this war and all my thoughts are with the Ukrainian people. Like most people around the world right now, I hope for peace and a swift end to the suffering happening in Ukraine."