The Manchester United star will be sidelined for six weeks with a damaged hamstring.
Pogba, 24, pulled up in Tuesday night’s Champions League win over Basel at Old Trafford.
The France international left the ground on crutches and had scans yesterday.
And United boss Mourinho says he doesn’t know when Pogba will be fit, adding he has strong back-up options to choose from.
“I don’t know [when Pogba will return],” said Mourinho.
“I just know that it’s a muscular injury, he’s out for the weekend match and that’s the only match I’m thinking about.
“I don’t think any further than that. He’s not playing this weekend. I just know it’s a hamstring problem.
“There are good players more than ready to play so honestly we miss Pogba, we need Pogba, but we have good players - Herrera, Fellaini and Carrick are waiting for a real chance to start the matches.
“We lost important players last season during crucial moments of the season and we weren’t crying or getting excuses in about that.
“Squads are there to try to cope with these kind of situations. I don’t know how many, but we’re going to play without Pogba for a few matches but we have other players.”
