The scandal-hit German carmaker said it was “considering further evolving the leadership structure”.
Mr. Mueller became VW chief executive in September 2015 following the diesel emissions scandal.
German reports suggested that VW brand Chief Herbert Diess would replace him, but the firm said no decision had yet been made.
The company said chairman Hans Dieter Poetsch had been talking to members of the supervisory and executive boards about moving or replacing some of them, adding that Mr. Mueller “signaled he was open to play a part in the changes”.
Mr. Winterkorn had resigned following the “dieselgate” scandal in 2015, when the firm admitted it had manipulated 11 million diesel vehicles worldwide to evade regulatory emissions tests.
Mr. Mueller has presided over a wide ranging restructuring of the company and its 12 brands.
However, in May 2017, prosecutors in Stuttgart said they were investigating the VW boss over suspicions he may have known about the diesel cheating before it became public.