Wolfsburg coach Dieter Hecking has claimed that speculation linking Kevin De Bruyne with Manchester City is affecting the player.
The 24-year-old midfielder has been heavily linked with a switch to the Etihad Stadium, with City reportedly lining up a formal bid.
"Kevin is a bit tired at the moment because there is so much happening around him," Hecking told Bild.
"He finds himself in a situation that is on his mind all the time, just like it has been over the past few weeks.
"We are just trying to get him in the best shape possible."
Wolfsburg got their Bundesliga campaign off to a positive start on Sunday with a 2-1 win over Eintracht Frankfurt.