United would secure top spot in the group by avoiding defeat to CSKA, who are also still in contention for a knockout berth.
"He's happy to play tomorrow", said Mourinho said.
"He is okay but he needs, now and again, specific work on the muscle that supports that knee that went through such a hard surgery", the boss told us. "His cycle of work will be over after CSKA". "He will be out again for tomorrow, but I believe he will be back to normal work after CSKA".
Asked if he had ever worked with a better goalkeeper than De Gea, Mourinho quipped: "Yes, Romero".
He said: "Romero is the best because he plays and my goalkeeper is always best in the world. Romero first, Joel [Pereira] second and David third best". So now David is the third best.
'Our young players will have something to learn from him playing in the game but at the same time we can not allow him to play at his best and show everything he is capable of'.
Shaw has made a mere 32 appearances in three and a half years at Old Trafford, and his current manager, Jose Mourinho, has often singled Shaw out for criticism in comments to the media.
"More importantly, the others deserve an opportunity to play".
In short, United are not going to suddenly deliver the worst defensive display in their history, but they will be keen to put this game to bed as early as possible before focusing on the massive Premier League clash against Manchester City just a few days later. We didn't qualify yet and I need to keep a certain balance in the team.
Asked if Luke Shaw might feature, the boss said: "He's working to have an opportunity and sooner or later, the opportunity will arrive". Selected for tomorrow, yes, for sure.
United need only avoid a heavy defeat against the Russians to ensure they top Group A and book their place in the draw for the last-16 on December 11.