​Bayern Munich coach Carlo Ancelotti has admitted he is unsure whether Robert Lewandowski will be fit to face Real Madrid in the first leg of the Champions League quarter-final on Wednesday night.

The prolific striker was forced to withdraw with a shoulder injury in the second half of last weekend's 4-1 win against rivals Borussia Dortmund.

Ancelotti originally claimed the knock was not serious, although he has now revealed Lewandowski will need to be assessed before kick-off.

Bayern Muenchen v Borussia Dortmund - Bundesliga

"Robert Lewandowski trained today, just 20 minutes because he had a problem in the last game," Ancelotti said - via ​Goal.

"This morning he had a good sensation. We will check definitely tomorrow. If he doesn't have pain he is going to play; if he does have pain he will not play."

He added: "Of course we have to control what he thinks – he had a good sensation in 20 minutes of training.

"I don't know really tomorrow if he will be ready or not. We have to wait but this doesn't change our idea of the game, our strategy and the confidence we have for this game."

Lewandowski took his tally for the season to 38 goals in 40 games in all competitions with a brace in Der Klassiker.

Bayern goalkeeper Manuel Neuer will return against Real Madrid having been absent from his side's last three Bundesliga games with a foot injury, but defender Mats Hummels will be out with an ankle problem.