Manchester United's Marouane Fellaini could face up to six weeks out following wrist surgery and a seperate back injury leaving the Premier League champions short in midfield over the festive period.

Fellaini, 26, is struggling to recover from back surgery prompting the decision from the club to strike while the iron's hot and schedule much needed wrist surgery which had previously been delayed.

"We thought his back would be OK after 10 days but it wasn't getting any better," said manager David Moyes ahead of Boxing Day's game against Hull.

"We made a decision to get his wrist operated on - get it done quickly."

He added: "We think it will be six weeks but there's a chance it will be shorter than that."

The Belgian international has been playing with a wrist problem ever since the Champions League draw with Shakhtar Donetsk in October but his back injury came during United's defeat to former club Everton earlier this month.

United midfielder Michael Carrick remains out with an achilles injury and his return is yet to be confirmed.

"His back problem was just going to take time," said Moyes.

"The back problem was a muscle injury in his back which wasn't healing so it was maybe going to take longer than expected. That's why we decided to get the wrist done.

"It is unlucky. He doesn't feel 100% fit because of the wrist, he is finding it difficult. We thought the best idea was to move on and give his back plenty of chance to get well as well."

Fellaini, who moved to United in the summer will now miss the busiest period of the season as the club look to turn around their fortunes in the hope of challenging for the title.