Bayern Munich coach Carlo Ancelotti has conceded benching Franck Ribery for last week's 2-1 win over Freiburg was not an easy decision.

The Frenchman had to settle for a spot on the bench as Ancelotti preferred Douglas Costa instead, with Ribery eventually coming on for the final 20 minutes of the game, capping a fine substitute appearance with the assist for Robert Lewandowski's winner.

Ancelotti has another difficult decision to make when Bayern take on Werder Bremen on Saturday and he has acknowledged it will be tough to choose between both wingers.

"It is always hard for me to bench someone, especially with a professional like Franck," Ancelotti stated at a news conference.

"He is in great shape and could play without any problems. 

"The same goes for Douglas Costa. Costa has been better in training than he was against Freiburg. 

"Costa has different characteristics than Ribery, but they are both great for the team.

"The players are very professional, but I can simply not field all of them."

Lewandowski netted twice to help Bayern past Freiburg last week and Ancelotti will be hoping for another stellar performance from the Poland international against Werder.

"Lewandowski is in top form," he added.

"He is playing really well at the moment and I hope he can keep this up. I am very satisfied with his performances because he is doing well. I hope he can help the team in the months to come."

Bayern will be without Arturo Vidal and Thiago Alcantara at the weekend, but the duo are expected to be back in time for the games against Schalke and the Champions League clash with Arsenal later in February.

"Vidal and Thiago are not available, but they are in my plans for Schalke," Ancelotti stated.

"Kingsley Coman is fit and I am keen to give him some playing time against Bremen. He is not ready to start yet, but he is an option for us."