Bayern reliant on Robben firepower
The Netherlands winger scored the crucial goals that helped Bayern Munich knock Fiorentina and Manchester United out on away goals in the previous rounds.
Robben was again on target against Lyon as he gave his German side a 1-0 win in the first leg after Franck Ribery had been sent off. The Frenchman will miss the second leg through suspension.
"He's got a fantastic left foot and his right one helps him walk," Bayern midfielder Bastian Schweinsteiger, speaking about Robben, told reporters on Monday.
"We don't rely only on Ribery or Robben... but I think Arjen is able to score more goals," he added.
Bayern defenders Martin Demichelis, Daniel Van Buyten and Diego Contento are all doubtful through injury and coach Louis Van Gaal said his side would not have a defensive approach to the game despite their one-goal advantage.
Lyon, who had never played in a Champions League semi-final before, think their lack of experience cost them a lot in the first leg. They promised their fans they would not be as timorous on Tuesday.
"I think that we are paradoxically in a good situation now because my players play better when they have to try hard to get a result than when they have to control a situation," Lyon coach Claude Puel said.
Lyon have defence worries as well as Jeremy Toulalan is suspended after being shown a red card in the first leg.
Brazilian centre-back and captain Cris suffered a locked knee in Munich but said on Monday he should be fit for the game.