Centre-backs
Eric Bailly/Chris Smalling
The central defensive position is an area that has given Mourinho one or two things to think about. Given that he will not have all his players fully fit for the tie, his first pick ideally would be Bailly. He is a combative defender who can read the game well and has the speed to match many attacking players. He picked up a slight injury in pre-season and his full recovery will be crucial for United.
Smalling, on the other hand, has good experience in the Premier League. He proved last season that he too can be dangerous on set pieces by contributing four goals. Smalling struggled against Leicester last season with the presence of Maguire and Wes Morgan, proving difficult to deal with in set pieces. If Bailly is not fully fit, then he will be the natural replacement to start.
Phil Jones
He is not the most assured of central defenders especially in big matches but Mourinho's options are limited. Despite not playing much for England at the World Cup, he should get the nod in this one given that United are still concluding some transfer business for a new centre back.
If they succeed, it is highly unlikely that they will walk right into the starting 11. Jones played against Bayern Munich in United's final pre-season match and should be picked as a centre-back partner to either Bailly or Smalling.