Manchester United had a frustrating evening against Anderlecht in the second leg of their Europa League quarter-final in more ways than one.After Henrikh Mkhitaryan gave United an early lead thanks to lovely build up play from Paul Pogba and Marcus Rashford, they let the Belgian side back into the tie and conceded a precious away goal.The Red Devils had a plethora of chances inside 90 minutes with all of Pogba, Rashford and Zlatan Ibrahimovic guilty of being wasteful, particularly the latter.The last think boss Jose Mourinho would have wanted with 10 games still to play this season - at least - is extra time.However, things got a lot worse for Mourinho and United with what happen to Ibrahimovic with the very last moment in normal time.The nomadic Swede has been a revelation at Old Trafford this season after moving on a free transfer from PSG last summer.The 35-year-old has 28 goals in all competitions this season for United and the club are desperate for Zlatan to commit to another season in the red half of Manchester.However, as you can see from the video below, he might not be able to.

As the ball was launched into the box with United desperately looking to score in injury time, Ibrahimovic contested a header with the Anderlecht centre-half and came down awkwardly on his knee.

It looks horrible. It essentially bent the way it wasn't supposed to and the legendary forward received lengthy treatment at the full-time whistle before being stretchered off.

One has to assume that, if the injury is as bad as it looks, not only is Ibra's season well and truly over, but his career could be in serious jeopardy at his age.

At the time of writing, United have just taken a 2-1 lead after Rashford, who moved into the centre after Zlatan was stretchered off, finished low just inside the box.

With Wayne Rooney back on the bench, his return to the fold could prove timely if the fears about United's No.9's knee is confirmed.

Let's all hope the injury isn't as bad as it looks, but Zlatan's pained reaction told the whole story.