Manchester United have confirmed that Marouane Fellaini has had the wrist operation which is expected to keep him out of action for up to two months.
The Belgium midfielder underwent the procedure to repair tendon damage at a hospital in the North West over the weekend and is set to miss key Premier League games against Tottenham and Chelsea .
The £27.5 million summer signing from Everton sustained the injury playing against Shakhtar Donetsk in the Champions League in early October but has played since with a protective cast.
Fellaini has battled through in a bid to help when they have suffered other midfield injuries to players such as Michael Carrick.
However, the 26-year-old has endured a difficult time since joining the club, failing to make the impact manager David Moyes had hoped for and seeing his popularity with the club's fans fall.
He is yet to score for United in the League, been sent off and has also been troubled by a back problem.
That injury has sidelined him since the beginning of the month, Moyes explained at the weekend.
"Fellaini has got an injury to his back which we hope might have healed up but I'm going to send him for another scan," the manager said.
"If it hasn't healed up I might need to take a decision and get his wrist done as well. We hope his back would be only 10 days or so but he is still feeling it.
"It's a muscle that has separated from the bone in his back and that is what is causing the problem. We hoped it might have healed in 10 days or two weeks but he is not feeling much better today."