Lewandowski managed 30 league goals for the German champions last season, but a double for Borussia Dortmund's Pierre-Emerick Aubameyang on the final weekend saw the Gabon international finish top of the charts with 31.
The 28-year-old revealed his frustration immediately after the final game last month, and Lewandowski's agent Maik Barthel has blasted Bayern for 'not supporting' the striker.
"Robert told me that he got no support and that the coach gave no call to help him in the last game to win the top-scorer title," Barthel told Kicker. "He was disappointed as I have never seen him before. He really hoped that the team would support him proactively."
Lewandowski managed 43 goals in 47 appearances for Bayern in all competitions last season.