Berlin - Jerome Boateng could miss the World Cup for Germany after suffering a thigh injury in Bayern Munich's Champions League defeat to Real Madrid, according to a report on Thursday.
The world champions' goalkeeper Manuel Neuer meanwhile appears to be losing his battle to regain fitness in time for the finals in Russia, other reports said.
Defensive lynch-pin Boateng pulled up after a sprint in the first half of Wednesday's semi-final first leg and had to be helped off the field.
According to Kicker magazine, he could be sidelined for four to six weeks. Germany's first World Cup group match is on June 17.
Bayern coach Jupp Heynckes has already ruled Boateng out of the return leg of the semi-final in Madrid next Tuesday.
"It's a muscular problem for Jerome, he will drop out," said the Bayern boss, who is also waiting on news of Arjen Robben, who was injured in the opening five minutes.
Germany's head coach Joachim Loew will name his squad on May 15.
Having last played for Germany in October 2016, Neuer only resumed training with Bayern last week after seven months out with a metatarsal fracture.
With a month of the season remaining, neither Neuer nor Bayern have been able to give a date for his return.
"I'd obviously like to help the team again, but I have to wait to see how the next steps go," Neuer told Sport Bild.
"It's also important what the doctors say (about) at what point I can be involved again.
"On top of that, I have to be happy with my performance level and be honest with myself.
"There are a lot of question marks."
Former Germany international and TV pundit Dietmar Hamann has said he doubts Neuer will be fit in time for the World Cup.
Neuer is cautiously optimistic.
"I think I'll be there and will be able to play, that's what I want," Neuer told Stern magazine.
"I am happy with the way things have gone until now, but of course, I wish they were a bit further on."