Bayern Munich have said they will not put Robert Lewandowski's health at stake if he is not ready to face Barcelona in the Champions League.
Lewandowski suffered a broken jaw and nose as well as concussion after a collision with Borussia Dortmund goalkeeper Mitch Langerak in their DFB Pokal penalty shootout loss on April 28.
Bayern had said last week that they were "profoundly convinced" that Lewandowski would be available for the first leg of their semifinal at Barca on Wednesday, and the striker used his Twitter account on Sunday to say he was "ready for the next challenge."
However, the Poland international, who sat out Saturday's 2-0 defeat at Bayer Leverkusen, missed training on Sunday, and Bayern sporting director Matthias Sammer has said he will only play at the Camp Nou if he is fully fit.
"The doctors will decide it, along with the player himself and also [how he feels when wearing] the mask, but one thing's for sure -- no player in the world can be so important that you'd put his health at stake," Sammer told reporters after the Leverkusen defeat.
"Should the doctors give him the green light, the player has to make a decision: Can he handle it? How does he feel? Should everything be fine, he has a chance."
German football magazine kicker reported on Monday that Lewandowski's shoulder injury -- also picked up in the collision with Langerak -- could ultimately end his hopes of playing in the first leg.
Bayern's injury problems are mounting, with Arjen Robben already out for the rest of the season and Franck Ribery, who has been out for nearly two months with an ankle injury, given no chance of featuring at the Camp Nou.
Sammer had said late last month that there was no timeframe for when the France international may return, and he told ZDF at the weekend that he is "a long way from making an appearance" for the club, although kicker believes he may be available for the second leg.