Muller was an unused substitute as Bayern Munich beat RB Leipzig 3-0 last month in their last game before their winter break.
"The last game against Leipzig was not optimal for me personally, since I did not play," Muller told Bild.
"There was more space than in the games before. It was a game I could have enjoyed.
"Of course, I'm not sitting there with a grin on the bench."
The Daily Express says Manchester United are long-term admirers of Muller, who has won every honour available to him at club and country.
United manager Jose Mourinho may be interested in the 27-year-old were he to become available for transfer.
Bayern Munich legend Lothar Matthaus recently cast doubt over Muller's future by admitting he doesn't really fit in under Ancelotti.
"There is not really a position in Ancelotti's formation that suits him," Matthaus told Bild.