Ibrahimovic returned to action last month following his ACL injury.

The 36-year-old has made four substitute appearances for Manchester United since his return but was left out of the squad for Saturday’s win over Arsenal and will not feature this week.

But Mourinho hinted he could be involved in the Manchester derby next Sunday.

“Zlatan needs sometimes very hard work on the muscular area that supports the knee that had the problem,” he said. 

“And when the period for that hard work comes, also the fatigue comes. He was on this cycle of work, divided between the gym and the pitch. 

“And he will be out again for tomorrow but I believe back to normal work after CSKA."

Ibrahimovic was expected to be out until the new year after hurting his knee in April and missing the Europa League final.

But he stunned doctors by getting fit and returned against Newcastle on November 18.

He it yet to start for United this season and Mourinho’s comments suggest some rustiness.

Mourinho will again be without Marounae Fellaini, Phil Jones, Eric Bailly and Michael Carrick for a game that United only need a point from to finish top of their group. 

Mourinho refused to reveal whether Untied have appealed against Paul Pogba’s red card at Arsenal. But he did confirm that Pogba – who is facing a three-game ban – will play tomorrow.

“He is not suspended for the Champions League so he plays tomorrow.”

Asked how Pogba is mentally after a dismissal that rules him out of the Manchester derby on Sunday, he said: “He's happy to play tomorrow. It's the next match, the match that matters. He plays tomorrow.

“Of course he's a bit tired because it was a huge match last weekend and just two days to recover for CSKA.

“He's very happy to play tomorrow and try to keep his momentum. Since he was back from injury he's been phenomenal.”

Mourinho also confirmed that Luke Shaw will finally involved - either form the start or the bench.

The £28m former Southampton left back has made only two appearances as a substitute in the Carabao Cup this season largely because of the outstanding form of Ashley Young.

But Mourinho admits Shaw deserves some game time for his hard work in training.

“I have to think,” he said. “I am going to make a few, but not too many, changes. We didn't qualify yet, we didn't finish first in the group yet, there are other clubs also involved in qualification and I need to keep a certain balance in the team.

“When we speak about Luke Shaw you are right he's working to have an opportunity and sooner or later that opportunity will arrive because he deserves that opportunity.

"He is selected [in the squad] for tomorrow for sure....to start or be on the bench I cannot answer."

Mourinho confirmed that Sergio Romero will play despite David de Gea’s man of the match performance aginast Arsenal.

And he insists his side will hav eno problems focussing on tomorrow's game despite the importance of Sunday’s showdown with runaway leaders City.

“It is easy to focus on the CSKA game. We are used to it. We don't think about the next, next game - just about tomorrow.”