Manuel Neuer might not stay a Bayern. Photo: Wolfgang Rattay/Reuters

Munich Goalkeeper Manuel Neuer will not retire when his contract at Bayern Munich runs out in 2021 but might not renew with the German champions if he feels they will continue to struggle in Europe, his agent said on Saturday.

"He won't stop in 2021," Thomas Kroth told the Sueddeutsche Zeitung. "The phase in which he has to make a decision is coming. What are the prospects for the future? A contract extension and the end of his career at Bayern is, of course, the obvious choice. But not the only one."

The 33-year-old Germany stopper, part of the side to win Bayern's last Champions League title in 2013, has been troubled by injury the last two seasons but he remains fiercely competitive.

"Manuel is success-oriented. My impression is that the gap to the top four English teams is already big and that Bayern's squad is not yet positioned to take Manuel's goals seriously," added Kroth.