Mourinho last week dismissed as "lies" any talk of the Frenchman wanting to leave Old Trafford less than two years after he returned to the club from Juventus for a then world-record fee of £89 million ($124 million).
The midfielder has endured a frustrating spell in recent weeks, having been substituted twice and absent from the starting line-up three times in United's past five games.
He missed last Saturday's FA Cup fifth-round victory at Huddersfield because of illness but had been expected to return from the start on Wednesday as United visited Sevilla for the first leg of their Champions League last-16 tie.
He was named on the bench instead, but ended up playing most of the game anyway, replacing Ander Herrera, who was forced off early with a hamstring injury in the 0-0 draw.
With Herrera out of action, Pogba is set to return to the starting line-up when Chelsea visit Old Trafford in the Premier League on Sunday.
"You saw the game against Seville," said Mourinho. "It's always more difficult to come from the bench than to start.
"A player when he is starting the game has a different kind of preparation for it. To be on the bench and to come on without warming up and getting to the pace of the game is not easy.
"I think he had a very positive game for us. Some players on the bench take five minutes to be ready to play. They don't have shin pads, they don't have strapping, they don't have the shirt.
"He took 10 seconds to be ready to come to the pitch, to show the professionalism and show he was ready to help the team."
Mourinho attempted to play down his rivalries with both Chelsea and their head coach Antonio Conte.
Conte and Mourinho have traded poisonous barbs this season, culminating in the pair saying they felt "contempt" for each other.
Asked for his thoughts on their impending meeting, Mourinho said: "I don't want to speak about it. I'm not going to speak about it. That's not the point. He is a very good manager, they are a fantastic team and that's what is important for me."
Mourinho spent two spells as manager of Chelsea between 2004 and 2015, winning three Premier League titles.
His family home is still in London, near Chelsea's Stamford Bridge ground, and he said he retains a good relationship with many people at the club, citing the support they gave him after the death of his father last year.
Mourinho said: "I have a good relation with the board. I don't forget how nice they were to me in a difficult period with departure of my father. I don't have any problem, any regret, any stone in my shoes, no problem at all."