Bayern host Werder Bremen in the Bundesliga on Saturday, three days before the second leg against Real at the Allianz Arena, having lost the first leg 1-0 in Madrid last Wednesday.

Guardiola's side has produced a worrying string of lacklustre performances since winning the Bundesliga title at the end of March with a record seven games to spare.

Bayern suffered only their fourth defeat of the season at Madrid's Bernabau stadium on Wednesday, but Guardiola has said he was proud of the passion his side displayed and demanded more of the same against Bremen, then three days later against Real, as they bid to reach the Champions League final on May 24 in Lisbon.

"We must have the same passion we showed at Real Madrid," said Guardiola in Friday's press conference.

"I have to think about rotating the side, but I will decide after speaking to a few players.

"We need the same fighting spirit, I said after the defeat in Madrid that I am proud of the team and they way they played.

"We didn't expect that Real Madrid would have so few goal chances, but we have to react for Tuesday.

"We are 1-0 down and we have to attack more and we have two important games to get through now."

The sudden drop in form of Bayern's France winger Franck Ribery is a concern for Guardiola after the 2013 European player of the year struggled in Madrid as he has done in recent league games.

"It's a problem for the coach to find the right solution," said Guardiola.

"I have to support him and I speak to him everyday.

"He always fights for the team.

"The problem is not in his legs, it's in his head," added the Spaniard when asked if Ribery was still affected by surgery in February for a burst blood vessel in his buttocks.