Bayern Munich midfielder Thiago Alcantara has admitted he did not expect Douglas Costa to make his mark so quickly at the Allianz Arena.
Costa joined Bayern from Shakhtar Donetsk ahead of this season and has established himself as a key man in Pep Guardiola's side.
Thiago has been hugely impressed by the Brazilian winger, saying on Wednesday: "I already knew Douglas when he was still at Gremio and then at Shakhtar.
"But he still managed to surprise me when he came to Bayern with his pace on the ball and his superb technique.
"He is a great guy and a great player."
Bayern face Juventus in the first leg of their Champions League last-16 tie next week, but Thiago insists the German champions are fully focused on Saturday's Bundesliga clash with Darmstadt.
"We are not thinking about Juventus at all. We are entirely focused on Darmstadt," added the Spain playmaker.
"We can start thinking about Juventus after this weekend's game."