A week after key players Marcos Rojo and Zlatan Ibrahimovic suffered season-ending knee injuries that require surgery, Pogba limped out of the weekend win over Burnley.
And that muscular problem has ruled him out of the derby visit to the Etihad, a game which will have a crucial bearing on which of the Manchester clubs finishes in the fourth and final Championship League squad.
Pogba’s absence could be a major blow to Mourinho especially as he still has major problems in defence.
After the Burnley win, Mourinho challenged England internationals Chris Smalling and Phil Jones to hurry back from their injuries in time for the derby.
But the pair have not responded as their manager would have wished and remain sidelined for a game which sees Mourinho renew his fierce rivalry with City’s Pep Guardiola.
“Valencia is the only one,” said Mourinho. “We go with what we have, we fight with what we have. I trust the boys and we go with everything we have and we go until the last second of the season. We are fighters, the boys are fighters and we go.”
Mourinho also confirmed that Ibrahimovic has a scheduled surgery on his knee ligament injury in the United States although the manager has yet to publicly discuss his future at Old Trafford.
United and Ibrahimovic had yet to confirm whether they were to activate the second option year of the contract he signed when he moved to the Premier League last summer and, with the 35-year-old out for an estimated nine to 12 months, his prospects of remaining at Old Trafford are surely compromised.
Mourinho, however, would not entertain questions about Ibrahimovic’s United career.
“I don't know, I don't want to know, I'm not interested in it, I don't care about it,” said Mourinho. “I just want the difficult surgery to go and of course we think he's in fabulous hands and recover from the injury to prepare himself mentally for the next step.
“And I think the next step will always be something he really wants which is what I was saying before the injury in the period of doubts over his future.
“He’s much more important than myself and what I want, it’s what he wants. I always want the players to be happy, to choose their future and I think this is what’s going to happen.
“But now before such an important surgery I think it's a waste of time to speak about what next.”
Whether the striker plays for United again, Mourinho seemed in no doubt that Ibrahimovic will play again.
The cult hero posted a picture on social media within days of his injury against Anderlecht insisting he will fight back and Mourinho has no doubt he will succeed.
“The future is a big surgery, a long period of recovery but the future is also in the hands of a very strong guy, mentally very, very strong, who wrote immediately on his social media that he will stop when he wants, not when people think,” he said.
“So it looks to me he will not give up and will fight and I’m really pleased with that because that’s the Zlatan I know.
“He fought all his life, that’s what I told him, ‘You fought all your life since you were born, I don’t see a reason for not fighting now.’”