United endured two more layoffs in their 1-1 draw with Swansea with Luke Shaw and Eric Bailly both forced off early.
Left back Shaw was withdrawn after just nine minutes and centre back Bailly after 61 minutes – both with suspected ankle knacks.
The defensive injury list now stands at SIX – with Marcos Rojo, Chris Smalling, Phil Jones and Timothy Fosu-Mensah already sitting out of action.
Mourinho, who had Juan Mata back from a groin operation, is also without Paul Pogba and Zlatan Ibrahimovic.
“I don’t know about the injuries,” Mourinho said. “I think Luke Shaw’s must be a big injury, because to leave the pitch after 10 minutes I am expecting a very big injury.
“At the moment, we cannot walk from the bed to the toilet without breaking a leg.
“I prefer not to speak about Phil Jones and Chris Smalling. I prefer to speak about Juan Mata giving everything to be available. I am grateful for that.
“We will give everything on Thursday. That is sure. Whether we go to the final or not doesn’t matter, I am really happy with the guys.”