Where to watch
Kick-off is at 3pm GMT. Catch the highlights of the match on Match of the Day on BBC Two and BBC Two HD at 10pm GMT.
United registered a comfortable 3-1 victory over Sunderland as David Moyes left Old Trafford in disappointment on his first return to his former club since he was sacked by the Red Devils in April 2014.
Daley Blind helped the Red Devils get a lead in the first half. However, things changed in the second half after two substitutes, Henrikh Mkhitaryan and Anthony Martial added more pace on the wings.
Zlatan Ibrahimovic doubled the lead before the Armenian international scored one of the best goals of this season. Jose Mourinho will be looking to finish the year on a high with another victory on Saturday.
Middlesbrough enter this fixture after suffering a 1-0 defeat at the hands of Burnley. It was Victor Valdes' error that allowed Andre Gray to score in the 80th minute and that was the difference between the two sides.
Aitor Karanka will face his mentor Mourinho when his side makes a trip to Old Trafford. He knows that it will be hard for him to beat a side that is managed by the Portuguese tactician and the pair will keep the friendship aside when the two teams face each other on New Year's Eve.
The clash will also see United's former players Valdes and defender Fabio da Silva return to Old Trafford with their current club. Middlesbrough will be looking for a win, while the Red Devils will be looking to further extend their unbeaten run on Saturday.
What managers say
Jose Mourinho: "Honestly, I don't think so. I hope so. I would like to have him [Rooney], he's always a player I would like to have but I have my doubts. Let's see the evolution [of the injury]. It's a strange muscle, a big muscle surrounded by others and you can have an injury there but still be able to move well. He was not feeling very confident. It's not a big deal but, in four days, I have my doubts," Mourinho was reported as saying by the Daily Mail.
Aitor Karanka: "I have to say thanks to him [Mourinho] and to his staff so many times. I am in the Premier League because I learnt a lot with them. They gave me the last push to become a manager. We are really good friends and have a really good relationship. Sometimes I analyse them and I find similarities with us. But I have to do something different because he knows me. I will try, but it's difficult to surprise Jose. It will be a special moment for me and for the team, but it is football, and three important points to play for. In those 90 minutes you can't be friends. I never go to a game aiming for a draw. We will go to Old Trafford preparing and trying to win," Karanka told Sky Sports.
Betting Odds (betfair)
- Manchester United: 1/4
- Draw: 5
- Middlesbrough: 14
Possible XI: De Gea; Valencia, Jones, Rojo, Blind; Pogba, Herrera; Mkhitaryan, Mata, Martial; Ibrahimovic.
Possible XI: Valdes; Chambers, Gibson, Friend, Fabio; Forshaw, CLayton, De Roon; Downing, Begredo, Ramirez.