Bayern Munich captain Philipp Lahm says there are no guarantees that Thomas Muller will stay at the club amid links to Manchester United.

Reports in the German media have suggested that the Premier League side are preparing a second raid on the German champions after securing the signing of Bastian Schweinsteiger earlier this month.

Full-back Lahm offered no assurances to Bayern's supporters that his fellow Germany World Cup winner would not follow Schweinsteiger to Old Trafford, where he would be reunited with former Bayern boss Louis van Gaal.

"It's not my decision," Lahm told reporters in China, where Bayern are on a pre-season tour. "Things can happen very quickly in football.

"I certainly can't provide any guarantee for Thomas [not leaving]."