The Belgian striker has missed the last three games - and the prospect of his return has not gone down well with United fans who fear his reintroduction could upset a winning formula.
Jose Mourinho told this morning's press conference that there were no new injuries sustained in the memorable 2-1 Champions League success against Juventus.
"Yeah, Lukaku is training with the team this morning," Mourinho said. "If the answer is positive and we have of course one more session tomorrow, if the answer is positive he's ready but in this moment I can only say he trains with the team, I don't know his answer."
Mourinho was asked why United have been able to find a way of winning so late on in games.
"We can go to the other side, why we always concede before opposition," said Mourinho. "In a positive way it is easy to feel a team that does not give up, always find a way to fight back sometimes changing results, sometimes not.
"We are a team that has that collective spirit to fight back but is not always possible. If we keep conceding goals before the opportunity there will be a day where we cannot come back so we have to grow up in our approach, because is clear the team is growing up, but we have to grow up in our compactness and start matches well. Against Juventus it happened, we concede the goal min 60 or something like that and we had a good start. In the first 15 or 20 mins we were totally in control.
"We are going to try, I cannot say we are going to be successful in our motivations, in our desire, but we played two diff matches away against two very good teams Cheslea and Juventus and we managed to get good results and even if the good results were not in our pockets the performances were there, the positive attitude was there so we are going to try but Manchester City are a very powerful team."