Bayern Munich lost two players to injury in their Champions League semifinal first leg, as both Arjen Robben and Jerome Boateng limped off in the first half.
Robben, 34, sat down on the pitch after just six minutes with an apparent muscle problem.
Teammate Javi Martinez motioned to the bench for a substitution, and Thiago Alcantara came on to replace the Dutchman.
Later in the first half, after Joshua Kimmich had given Bayern the lead, defender Boateng also headed gingerly to the tunnel after picking up an injury in the 34th minute.
Niklas Sule came on for Boateng, leaving Bayern with just one substitute for the rest of the game.
Marcelo equalised for Real Madrid shortly before half-time.