Carlos Baleba and Kobbie Mainoo finally had the chance to start together against AS Roma in the Champions League, and despite the scoreline, they were impressing in midfield. 

However, Baleba was forced off early in the second half after pulling up and holding his hamstring. 

Michael Carrick has not revealed the extent of his injury, but he will not feature against Aston Villa and could be out for some time. 

Youri Tielemans replaced Baleba on Tuesday evening in what became his best performance in a Manchester United shirt. 

Tielemans has not had an easy time since moving to Old Trafford for £35 million in the summer, but his quality is well known. 

Speaking on the Belgian's cameo against Roma, Carrick told MUTV: "Yeah, I thought he came on and, in the circumstances, he was absolutely fantastic, Youri, with his experience and his leadership.

"He’s seen it before, done it before, kind of had that aura about him when he came on the pitch, and everyone kind of went with that." 

Signing Tielemans for just £35 million what seen as a coup from many supporters, and his performance against Roma is a good sign of things to come. 

"That’s why he’s here, because he can cope with those sorts of moments and knows what it feels like and calms everybody down. I thought he was really good.

"Obviously, a game against his old club, he’d be looking forward to that as well, but I was really pleased with him the other night."

Manchester United face Aston Villa on Sunday afternoon, which will be Tielemans' first time playing against Unai Emery's side since leaving them in the summer. 

Without Carlos Baleba, Michael Carrick will be forced to make a change in central midfield, with Andrey Santos and Youri Tielemans the main contenders for the position. 

Santos offers more defensive security and running power, while Tielemans is better at progressing the ball and finding space in the opposition's defensive line. 

Despite concerns from the fans, Carrick has not been afraid to play Mainoo and Tielemans together this season. However, Santos' best performance for the Red Devils came in his last appearance against Chelsea. 

Losing Carlos Baleba is a huge blow for Manchester United, even if he has not been at his best so far this season. Carrick will know that neither Santos nor Tielemans will be able to replicate Baleba's off-the-ball work, but not many can. 

Tielemans was on the pitch for all of United's goals against Roma, which could give him the nod over Santos, though it could see Mainoo asked to play a more defensive role than he did on Tuesday. 

Midfield is not the only tough area to choose this weekend, as Shea Lacey's performance should be enough to earn him a start, but that will force Amad to the bench. 

Michael Carrick also has a decision to make in the backline, with Patrick Dorgu likely to return to the matchday squad after a week of training.