Live coverage is on BT Sport 1. The Iceland global would need to play one of his better games of the season if Swansea are to salvage even a point at Old Trafford.
United will be without suspended midfielder Marouane Fellaini, following his sending off at the Etihad, while Paul Pogba (muscle) and Juan Mata (groin) are both still missing.
"You think through everything, every day until you go to sleep and again first thing in the morning". United will be pushing for a win, but the lack of options in the defence and midfield will force them to find solutions for this tie.
But it was Paul Clement's struggling visitors who came away from The Theatre of Dreams the happier of the two sides, after holding Jose Mourinho's men to a drab goalless draw - on Federation Internationale de Football Association 17 anyway!
But they were boosted by last weekend's 2-0 home victory over Stoke and the influential return of club captain Leon Britton. Fernando Llorente opened the scoring in the 10 minute before Tom Carroll double the lead with a deflected shot from outside the box. A loss against the Red Devils will be a massive blow for Swansea as they are fighting to stay in the Premier League. Before the game when asked if it was correct for the club to let players like Morgan Schneiderlin, Bastian Schweinsteiger, Memphis Depay and Paddy McNair leave, Jose said the decision was made by the players and not the club. And Timo Mensah, emergency like (against City) to help the team, strong legs, energy, but it's another one that we miss. "We will fight with everything we have".
Wayne Rooney scored a controversial penalty at the end of the first half after Lucasz Fabianki was adjudged to have fouled Marcus Rashford, but United were dealt another setback as Eric Bailly - Mourinho's only fit centre-back - had to be replaced after the break with an ankle problem. It's Axel, Eric and Daley [Blind].
"Leicester and Crystal Palace will not be easy - you've seen what they have done against Arsenal and Liverpool. I just had to keep training hard and trying to do well when I got the chance to restore the manager's confidence in me".
That led Mourinho to joke he might name himself in the starting side, along with youngster Axel Tuanzebe whose entire first-team experience amounts to 22 minutes as a substitute against Wigan in the FA Cup. Mourinho would have us believe that he is focusing on winning the Europa League, but his post-match comments on Thursday suggest that he has not given up on top four either.
"They had more of the ball, more chances, but my players were unbelievable the way they fought". But one of them is severely constrained by a fixture list that refuses to ease and an injury crisis that will force the manager's hand.
"We are so happy to have him back because he has a special talent", Guardiola said.