Marcus Smith was ruled out of England’s World Cup semi-final against South Africa because of concussion, head coach Steve Borthwick has confirmed.

Smith has been replaced at full-back by Freddie Steward after he took a series of blows in the last-eight victory over Fiji that resulted in him finishing the match with a bandaged head and fat lip.

A tackle by wing Vinaya Habosi forced him to undergo an HIA which he passed, but he failed the subsequent return to play protocols and has been stood down for Saturday’s Stade de France showdown.

England have made two further changes to their starting XV with prop Joe Marler and lock George Martin coming in for Ellis Genge and Ollie Chessum respectively.

“Marcus was unavailable for selection due to the return to play protocols. He was ruled out earlier in the week,” Borthwick said.

“He took a knock in the game and passed the first parts of the HIA process, which meant he finished the game.

“Then there are subsequent parts of the HIA process and one part of that he did not pass. And then it was confirmed to me he was unavailable for selection.

“He is perfectly fine in terms of symptoms – he doesn’t feel anything. We’d expect him to be available for selection after this weekend. It’s right to reiterate that player welfare is critical and vital to us.”

Whether a fit Smith would have been retained at 15 is unknown, but it appears unlikely given the precision and variety of South Africa’s kicking game.

Smith offers a cutting edge in attack but Steward is one of the game’s most accomplished full-backs – ultra-dependable under the high ball, strong in defence and a key component of England’s kick-chase.

Captain Owen Farrell is aware of the aerial onslaught coming in Paris but is backing Steward to thrive.

“The thing about Freddie is everybody knows how good he is in the air, everybody knows what a fantastic player he is in general,” Farrell said.

“But it’s the want to do it, the want to be in those battles, the want to go and get the ball back for his team, the want to defuse what’s coming our way. He is one of the best in the world at it.

“The kicking game has been a massive weapon for South Africa for years and years now. They’ve progressed it and they go on with a lot of contestable kicks.

“We’ve done our work and we’ve come up with our plan to negate what we can from them but also looking to be able to attack ourselves.”

The adjustments to the tight five see Marler’s scrummaging prowess get him the nod ahead of Genge, with Borthwick noting that South Africa have the “best scrum in the world”.

Martin will bring physicality to the second row while Genge and Chessum will take their place in England’s answer to the ‘Bomb Squad’ – the heavyweight forward reinforcements that the Springboks summon from the bench.

South Africa this week rejected the suggestion that in their quarter-final victory over France they used HIAs to rotate forwards Mbongeni Mbonambi, Pieter-Steph Du Toit and Duane Vermeulen, enabling them to take a rest.

Director of rugby Rassie Erasmus has a reputation for taking an innovative approach to the laws and testing their boundaries, but Borthwick has faith in the officials to spot any mischief.

“We have got a match officials team that’s world class, led by Ben O’Keeffe,” Borthwick said.

“I am sure everybody around the pitch as well will have every bit of process in place. There is no issues there from our perspective.”

England second row Ollie Chessum insists revenge is not a motivating factor for Saturday’s World Cup semi-final against South Africa.

The rivals collide for the sixth time in the tournament’s history with the most recent of those meetings taking place in Yokohama four years ago when Eddie Jones’ side were toppled 32-12 in the final.

Having demolished New Zealand a week earlier, England were expected to topple the Springboks but instead they were off the pace from the start and overwhelmed as a consequence.

There should be at least eight survivors from that starting XV who take the field for the rematch at Stade de France, but Chessum denied there was a score to be settled.

“It hasn’t been mentioned much, certainly by me anyway. I wasn’t here in 2019 so it doesn’t motivate me,” the Leicester second row said.

“We have got a new group of players now who are quite happy to leave that in the past and focus on what we can do as this new England group.”

Predictions of the semi-finals being comprised entirely of Six Nations sides have failed to materialise with England the sole European representative and the only unbeaten team left in the competition.

They face one of the great South Africa sides who have been installed as strong favourites to emulate New Zealand by winning back-to-back World Cups in the wake of their victory over France in the previous round.

Defence coach Kevin Sinfield has said that England were “in awe of the physicality they brought” against the hosts and Chessum insisted the Springboks must be matched in the forward exchanges.

“These are the games you want to be a part of – against the biggest teams on the biggest stage in the biggest competition,” Chessum said.

“They have some unbelievable players in their pack. They bring an exceptional level of physicality. It’s up to us to go out on the weekend and compete against that.

“South Africa are unbelievable across the board and we have got to be the same, if not better.

“We are definitely hoping for another step from us. That’s been the nature of the competition. Week by week we have grown as a group and got better in various aspects of our game.

“It’s important that we bring the physicality, but also the level of execution as well.”

England have a settled team and will make only minimal changes to the starting XV that overcame Fiji in the quarter-finals.

The biggest area of debate is at full-back where Steve Borthwick is weighing up the high ball and positional expertise of Freddie Steward against the cutting edge in attack provided by Marcus Smith.

Smith, a converted fly-half, has made only two starts and three replacement appearances in the position and his lack of experience could be exposed by South Africa’s accomplished kicking game.

Owen Farrell’s impressive display against Fiji appears to have brought his duel with George Ford for the number 10 jersey to a conclusion, but Kyle Sinckler could return at tighthead prop.

England’s second row giants Maro Itoje and Ollie Chessum have told Steve Borthwick they do not want to be rested against Chile.

Borthwick is expected to overhaul his starting XV against the weakest opposition England will face in their World Cup group campaign, taking the opportunity to give some of his stars a breather.

Itoje and Chessum have started the last three Tests together, including the Pool D victories over Argentina and Japan, and are candidates to be given the weekend off given the tougher assignments that lie ahead.

But Itoje is eager to retain his place in the starting XV – even though Chile are placed 22nd in the global rankings.

“I always want to play. I want to put my hand up for selection, I want to play for England. If there is an opportunity to play, I want to play,” Itoje said.

“You can’t take these moments for granted, you never know when the last time is that you’re going to play for England. I want to get as many caps as possible so I definitely would want to play.

“Steve has the big plan and he has to look after the whole squad, not just individuals. He is the final decision maker.”

The challenge facing Borthwick is to ensure his key personnel are battle hardened for the quarter-finals, which England have all but reached after dispatching the Pumas and Brave Blossoms.

Yet the break week each team observes at different stages during the World Cup means that after Chile their next assignment is the final group game against Samoa on October 7.

Itoje could therefore go three weeks without a game if he is omitted from the team that will be named by Borthwick on Thursday.

“A three-week break is neither here nor there. If I play – great,” Itoje said.

“When you’re not playing you do way more fitness. The guys who haven’t been in the squad have been getting flogged – so that’s motivation enough to play,” Itoje said.

“If I’m not playing I’ll be getting flogged. I’d much rather play because I don’t want to get flogged!”

Chessum, Itoje’s partner in England’s first choice engine room, is is also looking to keep his place, although the Leicester lock has a stronger case for inclusion as he is on the comeback trail from a serious ankle injury.

“You want to hold your hand up to play at every opportunity possible,” Chessum said.

“I have not played a lot of rugby at all in the last six months so I want to keep playing.

“It is not up to me, it is up to the coaches so I will hold my hand up in training this week and it is up to them, the selection process.”

Chile are expected to be overrun in Lille on Saturday but Portugal and Uruguay have already demonstrated against Wales and France in this World Cup that the minnows can cause a scare.

The tournament’s last great upset was when Japan toppled Ireland four years ago and Chessum does not want England to be the next big-name scalp.

“If you sleepwalk into games or sleepwalk into anything in this World Cup you will get caught out and exposed,” he said.

“You have seen from the games last week that there is not a big disparity between the teams – the tier-two nations have taken some of the best teams right to the wire.

“We will be firing on all cylinders in training and on the job to take the game to Chile.”

Ollie Chessum knew from the reaction of his England’s team-mates that he had done some serious damage as his World Cup dream flashed before his eyes.

Chessum faced a battle to be fit for the tournament hosted by France when a “freak training accident” during the final week of the Six Nations left him needing surgery to repair a dislocated ankle.

It was a savage end to his season but England’s breakout star of the Championship had already done enough to convince boss Steve Borthwick that he should be given every chance to prove his fitness for the World Cup.

Now two matches into his comeback, the Leicester Tiger is set to join Maro Itoje in the second row for the crucial Pool D opener against Argentina on September 9.

“I got a tackle from behind and I got my foot caught. It was just a freak training accident,” Chessum said.

“Initially I just thought I’d rolled it, but as I rolled over and the lads were around me, I saw them all turn away and that’s when I knew I should probably have a quick look – and my foot wasn’t where it was supposed to be.

“When I first did the injury one of the first things I said to Freddie Steward was ‘that could be my World Cup’, and he said ‘don’t think like that’. I was quite emotional at the time.

“There have been days in the last five months where I’ve thought it doesn’t feel great, but getting back was always the goal.

View this post on Instagram

A post shared by Ollie Chessum (@olliechessum)

“We knew it was going to be close. I spoke to the surgeons and they said it would be four to six months and with no setbacks, that would be a semi-realistic goal.

“But then I had conversations with some of the physios and they said that they’ve had lads who have had similar injuries that have taken seven to nine months.

“I just cracked on with it. If it happened, it happened. And if it didn’t, it didn’t.

“It’s still not 100 per cent now. There is enough there that I can do what I need to and I can play rugby, but the likelihood is that for the next year or two I will need to look after it.”

Ollie Chessum is in contention to win a place in England’s World Cup squad after making a successful early comeback from the ankle surgery that had jeopardised his tournament hopes.

England feared they had lost their breakout star of the Six Nations after he was ruled out for between five and six months with the injury sustained during preparations to face Ireland in March.

But on Tuesday he took part in a live scrummaging session during training as he closes in on making a complete recovery that should see him named in Steve Borthwick’s 33-strong squad on Monday.

England had made it clear Chessum would not be risked in Saturday’s opening warm-up match against Wales in Cardiff if not fully fit, but would be willing select him for the World Cup on the strength of his performances this year.

“Ollie’s close to a return. He’s done incredibly well and has been so diligent with his rehab. He looks really good,” attack coach Richard Wigglesworth said.

“He’s definitely a great character and I’ve enjoyed working with him over the last few years, but he’s also a top-quality player who we are keen to get fit.

“The medics said that if he’s free of complications then there’s a very good chance of him being ready for the World Cup. He’s had no complications and flew into his rehab.

“I don’t think we’re going to rush someone back from that injury and say ‘you have to play (against Wales)’ – it’s up to us to make a decision on the best 33 on the back of all the evidence we’ve had.

“Ollie has obviously given pretty strong evidence that he’s a top international player when he was fit.”

Chessum won the first of his nine caps under Eddie Jones but it was during the Six Nations that he announced his arrival as a high-calibre Test player through a series of imposing displays in an otherwise-underperforming team.

The 22-year-old can play lock or blindside flanker and made a big impression on Wigglesworth, who played alongside him and coached him at Leicester until leaving to join Borthwick’s coaching team at the end of the season.

“When Ollie’s fit and firing he brings an energy with him that’s infectious and he’s someone who’s just going to get better and better,” Wigglesworth said.

“He’s got a great attitude, great athletic ability and he’s got the mind to be in an England shirt for a long, long time if he keeps progressing the way he wants to.”

Billy Vunipola has also provided a fitness boost as he shows no adverse effects from his recent knee surgery, nudging him closer to regaining his place as England’s number eight.

“Billy looks highly motivated and he’s had a big impact in training, coming back in straight away,” Wigglesworth said.

“He’s shown his class and his form. His training is slightly modified but not much.”

Borthwick will oversee the final selection meeting in Cardiff on Saturday night before telling each player individually on Sunday whether they made the cut for the World Cup.

The date of the announcement means that the Principality Stadium clash will be the final opportunity for players to play their way into the 33.

“We pick a team to try and win a Test match, without a doubt, but it would probably be disingenuous to say we aren’t trying to get a squad ready for the tournament as well,” Wigglesworth said.

“We have to have a squad that is ready to play in France to the best of its ability. Will the same team play four weeks in a row? No, absolutely not. There will be changes throughout the four weeks.”