The Red Devils are through to the Europa League semi-finals and are still fighting for a top-four finish, but their squad has been hit by injuries to key players.
Here, Press Association Sport highlights the problems United are having to deal with.
JUAN MATA
Pre-season concerns that the Spaniard may struggle under his former Chelsea manager have been wide of the mark. Mata has impressed this season so it was a blow when he last month underwent surgery on a groin injury, with Mourinho saying the midfielder will be out until the ''end of May''.
PHIL JONES
The defender withdrew from last month's England squad with a foot injury that appeared to be sustained in a training ground duel with team-mate Chris Smalling. Mourinho hopes Jones will return earlier than his initial ''mid-May'' prognosis.
CHRIS SMALLING
Another injury picked up in England's March meet-up. Smalling was spotted soon after with his right leg in a brace and, like Jones, his manager hopes to have the defender back from the knee injury before mid-May.
MARCOS ROJO
So impressive this season, the Argentina international left the field on a stretcher against Anderlecht on Thursday night after recovering from one challenge, only to go down again minutes later. The apparent knee injury saw Rojo limp heavily through the post-match mixed zone, but the defender said he was ''okay''. Mourinho does not share that optimism.
ZLATAN IBRAHIMOVIC
United's top scorer hobbled off after landing awkwardly just before extra-time against Anderlecht, with his right knee buckling on impact. He suffered ligament damage and is likely to be out for several months.
LUKE SHAW
Already under the microscope this season after returning from a broken leg to public criticism from his manager, Shaw limped out of the Swansea game. It is unclear how he sustained the injury, going down off the ball when play was on the other side of the pitch. Mourinho revealed: "I think Shaw has to be a big injury to leave the pitch after 10 minutes."
ERIC BAILLY
Pulled up when chasing a ball back in his own half, he also limped off the Old Trafford pitch during the second half. Jose Mourinho said after the match: "Eric Bailly, I don't know... he played every game of the previous eight matches in April and today 60, 70 minutes more."
