After being left out of the starting XI by Mourinho, Pogba was called into action early in the first half when Ander Herrera was forced off with an injury.
And alongside Nemanja Matic and youngster Scott McTominay, the 24-year-old was under the cosh for much of the game as Sevilla searched for a first-leg advantage.
But a stunning reflex save by David de Gea in the first half ensured United kept an important clean sheet away from home.
Unsurprisingly Mourinho was asked about Pogba’s display after the match and though the United boss was happy with his £90million man, he was more effusive about McTominay’s performance.
“Pre-match I had 3 of 4 questions about Paul and he wasn’t even playing,” he said.
“I understand the question but if I was you I would ask about McTominay and he looked like a man with dozens of matches in CL.
“I think Paul made a big effort to try to give the team what I asked of him.
“Paul replaced Ander, he tried to bring to the game the same kind of qualities.
“He lost a couple of possessions but he also gave us stability because we had a good percentage of possession for the way we played.
“I am also happy with Matic, so I think the three midfield players had a good game and Paul was part of it.”
It was McTominay who had United’s only shot on target in the first half with a left-foot effort which was parried away by Sevilla goalkeeper Sergio Rico.
But United were once again indebted to De Gea for keeping them in the match when Sevilla threatened to break the deadlock.
De Gea made eight saves which was the most by a United keeper in a Champions League game since Edwin van der Sar against Barcelona in May 2011.
With Chelsea to come at the weekend, the loss of Herrera to injury will be a concern to Mourinho and the Portuguese suggested the 28-year-old was not fully fit.
He said: “He had a small injury that stopped him for the last couple of matches.
“The medical department gave him 100 per cent ready for last Saturday. We didn’t play him to give more work and more protection but it looks like he was not fully fit.
“The medical department gave him fully fit. He trained Saturday, Sunday, Monday and Tuesday.
“He looked fit, the way he was playing during the time on the pitch he showed that intensity that is only possible when you feel fully fit.”