The 33-year-old hasn't been shy in admitting his desire to leave the German champions in the current transfer window, despite the club's intentions to keep him or to sell on their own terms.
Pre-season is due to start on July 12, but Lewandowski has no plans to report for duty, says Marca.
The forward's ex-agent Mail Barthel has gone as far as to suggest that he would be willing to strike in order to get a move over the line.
"It was already considered that he would not appear for training," Barthel said, referring to when Lewandowski wanted to leave Borussia Dortmund to join Bayern.
"I trust Robert not to show up for training."
Bayern Munich, on the other hand, aren't expecting just drastic action from the forward and they expect him to act in a professional manner.
"I don't think about that at all," said honorary president Uli Hoeness. "He has a contract, and we are a constitutional state.
"We have decided that we will not let him go. Unless we could have found a replacement."