Robben signed for Bayern from Real in August as a potential replacement for the Frenchman.
But he says: "It's his choice, but I hope he stays. Here he is the big star, while there he will be one among others. Moreover, the two teams are identical.
"It is important for the team he's playing again, I'm very happy, Franck is a world class player.
"Thanks to him, the team jumps to another level, he brings a lot of quality, attracts the attention of many defenders and creates space for others."