VfL Wolfsburg coach Dieter Hecking says Kevin de Bruyne has been affected by Manchester City's summer long pursuit.
City remain determined to prise De Bruyne away from Wolfsburg for what will be a club record fee of over £50million.
"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."