Manchester City boss Manuel Pellegrini says goalkeeper Joe Hart will be assessed on Thursday to understand for how long he will be out of action.
The goalkeeper was a second-half substitute against Juventus in yesterday's Champions League defeat.
The Chilean rued missed chances after his side succumbed to a 1-0 defeat in Turin allowing Massimiliano Allegri's side to go top of Group D.
"Both teams played well and we were unlucky to lose this game," Pellegrini said.
"Mandzukic finished well, but we had chances to at least draw - but missed them.
"It was important to score the first goal. We had the first chance to score with Fernandinho, but we didn't take it.
"We tried to dominate the game and I am not unhappy the way we played because this is not an easy team or stadium to come to, but it is not the result we wanted.
"We have so many injuries it is difficult to continue the same pace, but we had the personality to do it and were maybe a bit unfortunate.
"I hope we beat Borussia and still finish top of the group because it is important to arrive in the knock out stages in first position.
"We have already seen a strong Barcelona. We hope our team will have more luck in the draw of the round of 16 this year but we will see.
"[Injuries?] As for Joe Hart – it is impossible to know how serious his injury is at this point.
"He has a problem with his hamstring and has had a problem in his back for the past week.
"We hope we don't lose him, but for if for some reason he cannot play I have trust in Willy Caballero.
"David Silva is working with the physio in Manchester and we will know more tomorrow, but Vincent Kompany has no chance to play this week. He is not running yet and will need at least two weeks more."