It was one of those sliding doors moments that arise so often in professional sport.

At the time, of England's two strikers for the Under-19s European Championship qualifier with Switzerland in May 2012, Will Keane seemed most likely to eventually be preparing for a World Cup semi-final this week, not Harry Kane.

"I'd never had any setbacks at that point," says Keane in a fascinating chat with BBC Sport.

"When you're young, you're fearless. The whole trajectory of my career was up. I made my senior debut [for Manchester United]. We won the Youth Cup. I was doing well for England. Everything was taking off."

Fate turned against Keane. He sustained a major knee injury near the end of the game and it was 16 months before he played again.

In that time, Kane completed loan stints at Norwich and Leicester and broke into the Tottenham team.

"It's timing," says Keane. "Some lads go their whole career and have a few niggles, but nothing derails them too much.

"That first injury was at a crucial time. I had my foot in the door. The feeling was I would probably have been around the first team.

"If the injury had happened a couple of years later, I might have been an established squad player. When I had it, I missed 16 months at a crucial part of the transition from reserves to seniors."

As Kane prepares for Argentina, Keane is spending the early part of this week at Champneys Springs in Leicestershire, one of 45 players taking part in the PFA's 12-week pre-season camp.

The initiative, now in its third year, is aimed at providing a competitive environment for out-of-contract players keen to find a new club.

At 33, Keane feels he has "a few years" left and has not abandoned hope of adding to his five senior Republic of Ireland caps, having made the reverse move of twin brother Michael by playing his youth football for England but seniors for the country where his dad was born.

"A couple of lads I know did the camp last season and spoke really highly," said Keane.

"I almost feel like I'm part of a squad, and we're away for pre-season. There are so many staff; medical, coaching, administrative, media.

"It's quite competitive and there are seven or eight games, so clubs can see you're playing. There's an app clubs can sign up to. It's like a PFA transfer list - all our training data goes on it. Clubs can contact us directly, so hopefully if you go somewhere, you can go straight in."

Keane is feeling quite relaxed about his situation. He was out of contract once before, in 2020, when Covid hit and Ipswich decided they didn't want to trigger a one-year option because of the financial uncertainties of that time.

Eventually, Keane went back to Wigan, one of eight clubs he has played for in a career of, to date, 335 senior appearances and 85 goals.

It was also the period when he altered his mental approach to the game.

That first devastating ACL injury would have been bad enough. But he also "ripped his groin" in United's FA Cup tie at Shrewsbury in February 2016.

It meant 17-year-old Marcus Rashford, not Keane, was on the bench for the Europa League tie against Midtjylland three days later when Anthony Martial was injured in the warm-up and had to pull out.

Given his debut by Louis van Gaal, Rashford scored twice and then added another two goals in the Premier League game with Arsenal that followed.

"I went to America for an operation, landed in Philadelphia, turned my phone on and saw he scored two more," Keane says.

At 23, Keane knew that day it was the end for him at United; the club he and his family supported, where it seemed so certain he would become a first-team player.

Worse was to follow.

"It was hard to take, but I had to move on. I got a good move to Hull, who had just been promoted to the Premier League," said Keane.

In his sixth game, he sustained another ACL injury and was out for 14 months.

"It was crushing," he said. "I missed the whole season, and we got relegated. A lot of the young lads still got good moves; Harry Maguire went to Leicester, Andy Robertson went to Liverpool, Sam Clucas to Swansea."

For Keane it was the start of a mental journey he didn't fully address until he got to Wigan.

"I'd used sports psychologists before and always tried to be positive and optimistic, but I started working with someone at Wigan who hadn't worked in football before," said Keane.

"He's a bit more of a spiritual psychologist. We focus on positive intentions, manifesting, visualisation.

"I'd tried everything in the box, and kept breaking down, so I wanted to do something a bit different.

"I wish I'd had that when I was younger, especially with the setbacks I had early on. It might have got me back into the right frame of mind.

"For any player if you've not got belief in yourself, and you're lacking confidence, you're not going to perform the way you can.

"I was around the first team at United, then I got the injury, had a few loans in the Championship where I didn't do very well and I started to doubt myself. Wigan catapulted me.

"Before that I should have backed myself. I played with a lot of those lads all the way through, and that's where I was potentially heading.

"If I'd focused on the mental part earlier, it might have been a different outcome.

"Even at times when I picked up injuries, maybe I had a bit of self-doubt which led to something going wrong. If I was in the right frame of mind, maybe one of those bad injuries wouldn't even have happened."

His old strike partner Kane, it seems, has no self-doubt.

"I remember when we were young, people said he wasn't mobile but technically, the time he put into his finishing and his obsessiveness to be the best in terms of shooting, you see it don't you?" said Keane.

"He's so sure of himself, because he's put the work in. He knows he's a complete striker.

"He's obviously got that belief in himself. He might miss one, but he's not going shy away from it. If he didn't have certainty in his mind, he wouldn't be as prolific.

"He's not arrogant, he's just got the confidence that sets top players apart."

After ending last season on loan at Reading, Keane left Preston when his contract expired.

He is positive about finding a club: "There's been a few chats. I'm sure they're aware of me. They might be looking for A, B and C targets, but when the season does start, if a club doesn't have a great start, there's a bit of panic and maybe things open up."

He is also hopeful for England: "It's a hard one because I played for England up until Under-21s, and then seniors for the Republic of Ireland, so I've got a foot in both camps.

"I am proud to represent Ireland. My dad was born there and moved to England. But I've also been born and raised in England, and my family's English."