Marcus Rashford will have a scan on his ankle after limping out of Manchester United's derby day success at the Etihad.
The forward was replaced by Mason Greenwood late in the second half with United already in control and leading 2-0.
A Bruno Fernandes penalty in the second minute and an early second-half goal for Luke Shaw extended United's unbeaten away run in the Premier League to 22 games and ended City's winning run at 21.
But the injury to Rashford could take some gloss off the win, with the United attacker going down after tracking back as United looked to hold on to their 2-0 lead.
Asked about Rashford's injury after the game, Ole Gunnar Solskjaer said: "I don't know. It's something with his ankle. When he sprinted 70 yards to save a goal, it showed the attitude of the boy. I think he went over on his ankle but we need to do a scan, I've not had time to speak to the doctor yet."
Rashford has been hampered by a shoulder problem as well recently and Solskjaer will hope he doesn't face a spell on the sidelines with the fixtures continuing to come thick and fast.
Edinson Cavani picked up a knock in training on Saturday that ruled him out of the derby.
United are back in action on Thursday when they welcome AC Milan to Old Trafford in the last-16 of the Europa League.
