Antonio Valencia tries not to think about that night any more, the indescribable pain, the fear that flashed through his mind when he looked down at his leg and realised it had been snapped like a dried twig, his foot hanging back to front. And, above all, the hideous sense that his four-year-old daughter, Domenica, was watching it all unfold in the Old Trafford crowd.

On the stretcher Valencia raised his arm towards the stands. At the time, it looked like he was thanking the crowd for their solemn applause. In fact, it was to show the tattoo of Domenica's name on the inside of his arm. "All I can remember now is the pain, the worst pain of my life," he says, "but my first thought was to do that for her and show her I was going to be all right."

This was in September, a Champions League night against Rangers, a seemingly innocuous challenge from Kirk Broadfoot and then those ghastly moments when Valencia's team-mates went over to see their stricken colleague then, one by one, turned away, covering their faces, and it became apparent to everyone inside the stadium this was an injury that could break a footballer's career.

What has happened since identifies Valencia as a remarkable man. His leg was mangled: a snapped bone, a dislocated ankle, ruptured ligaments. But he has not just returned to the team well ahead of schedule but done so with a vitality and impetus that has seen him supplant Nani, the club's player of the year, as a near-certainty to face Barcelona at Wembley .

"I never thought it could happen like this," Valencia admits. "I thought I might make it back for the last couple of games, maybe when the league had been decided. Or maybe play the odd weekend in three, something like that. To come back so soon and to be playing in decisive games from the word go ... no, that's not something I thought would be possible."

It is a testament to the Ecuadorian's courage and application because, though they never said it in public, there were obvious concerns behind the scenes at Old Trafford that Valencia might have suffered permanent damage. They had been in this position before. Alan Smith suffered the same kind of injury as a United player in 2006 and, by his own admission, has never been the same player since. For Valencia, a winger reliant on speed and reaction, there was a point when insecurity took hold.

"I was worried. You start to think about the other players who have had that type of injury and never really recaptured it their form, players who never really got back to the level they were at before."

He would take encouragement from his hours with the club's chaplain, John Boyers. "His kind words gave me inspiration." More was provided by Sir Alex Ferguson. "The manager came to see me in hospital, [the assistant manager] Mike Phelan as well. They didn't set me any targets, they just said: 'Look, these things happen in football, don't worry, take it easy, take all the time in the world, all the time you need, and everything will be fine.'

"I sat down with the medical people and started to talk about the process of getting back and it was only then I started to get my head right. I started to think: 'Yeah, I'm focused now, there is something to aim for.' But I was worried. Certainly in the initial stages, I was very worried."

The recovery was "boring at first," a daily grind of swimming, gymnasium work and hours upon hours inside a zero-gravity treadmill designed by Nasa to simulate what it would be like on the moon, and introduced to Carrington to allow injured players to build up their leg muscles. "I used that machine for the first three months," he says. "It was great because you can put in the same physical effort that you put in on the field without putting any strain or weight on your leg at all."

His comeback match was "the greatest feeling", coming off the bench for the second half of the FA Cup defeat of Arsenal in March. The first few games he was "a little tentative". He recalls the Champions League tie in Marseille and being annoyed at himself for not putting everything into a tackle. But that was a one-off. "Once you start to warm up and look at the players' faces, the adrenaline kicks in and you don't think about it so much."

The return of the man who was signed to take over from Cristiano Ronaldo has unsettled Nani, leading to a marked deterioration in form, but it has scarcely mattered such is the way Valencia has slipped back into the side so seamlessly. He has started almost all of United's big matches in the past two months, quickly dispelling the fears over his future, and at the same time reminding us why Wayne Rooney once said the first name he wanted to see on the team-sheet was that of the Ecuadorian.

"His is the first name I look for as well," Valencia says of Rooney. "When the manager tells us the team he always starts with the goalkeeper, then goes from right to left, so I am mentioned quite early on – but then I have to listen out to see if Wayne is mentioned as well. He is a bright, intelligent, gifted player, and it is a pleasure to play with him. Though, to be honest, I am happy to hit anyone with one of my crosses."

Despite six months out, Valencia played enough games to warrant a Premier League winner's medal. Now, there is the prospect of his first Champions League medal and it could well be that, if Carles Puyol plays on the left side of Barcelona's defence, this will be one of the key battles of the final.

"Of course we can win," Valencia says. "We are Manchester United, we are a big club and we will go there playing the football that we know we can play."