Buttner shone on Saturday in victory over Sunderland.
"In a short time we play a lot of games and the coach has already indicated that in this period the fitness of a player is important. I'll hold off, I have nothing to complain about. It suits me perfectly to be here," said Buttner.
"That I had not played leagues matches for a long time does not mean that my development stopped. Everyday I train with the world's best players and the club has always said to me that my time would come."