Zlatan Ibrahimovic's sad end will unleash remarkable Marcus Rashford at Manchester United

Zlatan Ibrahimovic doesn’t do stretchers. When he suffered a potentially career-threatening injury against Anderlecht in the Europa League, the giant Swede managed to hobble off the pitch unaided. As his later social media posting suggested, a man who prides himself on defying the ageing process was not going to allow anything as minor as a ruptured cruciate to precipitate his retirement. Only Zlatan can call time on his playing days.

But the truth is that injury has, in all likelihood, signalled the end of his relationship with Manchester United. He told us when he arrived in England that those writing obituaries of his career were being somewhat premature. How right he turned out to be. Sadly, now might be the time to re-post the eulogies. Signed on a one-year contract, it seems improbable the club will offer a new deal to someone who will not be able to play for a substantial part of next season, particularly not when he will be close to 37 when he is able to return.

It would be a huge disappointment if the relationship between United and the great Swede turns out to have been only the most fleeting. He may have gone after less than a full season but this is a player whose goals, skill and self-confidence lit up Old Trafford. Never less than magnificent to watch, even at his most frustratingly profligate, there was something compelling about him on a football field. That red United shirt fitted him to perfection. He always looked as if he belonged.

And yet the misfortune of seeing such a talent depart the scene should be tempered by this thought: look at the player likely to replace him. In Marcus Rashford, Jose Mourinho has the most compelling of options. What’s more, watching Rashford in action, observing his pace, his tenacity, his technique, it is hard to deny the insistence that the timing is felicitous. Now is surely the moment to utilise him properly. Not as a bit-part player, not as an occasional wing man but as the main striker, leading the line, terrifying opposing defences with the range and depth of his talent.

Here’s why. For much of this season, Rashford has looked like a player suffering from second album syndrome. After bursting on to the scene last year he appeared to be the complete forward. But as that initial adrenalin rush of enthusiasm faded, his game dipped. Mourinho was absolutely right in his analysis: this was a player who lacked nothing in his attitude, his approach, his work rate. What was missing was confidence. Not to mention goals. For a substantial period he couldn’t buy one.

There are plenty of reasons for that. One might well be exhaustion, mental as much as physical. Another that opposing defenders, no longer caught by surprise, had found ways to counter his skills. But equally potent is the theory that, with Zlatan’s arrival at the club last summer, he had been given clear evidence that he was not to be regarded as the main man. Sure, there would be games on the wing, or games in his preferred position as centre-forward when the big man was rested. But the ultimate responsibility of leading the line was to rest on someone else’s shoulders.

And the psychological effect of that is not insignificant. It tells a player that he is the understudy. An excellent one who earns the manager’s full trust maybe, but an understudy nonetheless. That sense of being a squad player can deflate a player’s self-confidence. Rashford, way too selfless a character to sulk or moan about his position, clearly maintained his full-on focus. But the effect of his demotion was evident in his declining effectiveness in front of goal.

As it happens, in the past month or so he has been playing as if re-invigorated, refreshed, restored. The goals have returned. At times – as when he started against Chelsea, or when he replaced Ibrahimovic against Anderlecht – he has been the match-winning force he threatened to be last season. Frankly he has looked unstoppable. He has looked like a player whose time has come.

Alex Ferguson was a manager who made a habit of spotting moments like that. He knew instinctively when the time was right to unleash youthful ability. He was prepared to take tough decisions to remove established players from their path to enable them properly to develop. Jose Mourinho may have been reluctant to admit it, preferring to rely on his old stager, but Rashford is at that point when he needs a substantial run in the first team, when he needs to be trusted, when he needs to be acknowledged as the main man.

With Zlatan around that would never happen. Mourinho would always pick the player. Indeed there were some among the United match-going faithful who assumed he would pick Zlatan even if he were hobbling around with his knee in small pieces.

The thing was, when the Swede did play he was the centre of everything. The others were obliged to cede to his superiority. Sure, they were richly rewarded this season for their subservience: 28 goals is some return. But they were the supporting cast.

Which suggests there maybe a silver lining in the dark cloud of his departure. It has forced Mourinho’s hand, left him with no option but to give the required space that Ferguson always understood was necessary to ensure a young player reached his potential. If time has been called on Ibrahimovic’s foreshortened spell in a red shirt, then there is compensation: Rashford is ready to take his place.