Lewandowski, who has been at the Allianz Arena for four years, recently appointed Pini Zahavi as his agent to spark rumours of an exit being on the cards.
However, Bayern chief Rummenigge is confident that, much like 10 years ago when it came to fending off Chelsea's interest in Franck Ribery, the Bundesliga giants will once again keep hold of their star man.
"I always like to remember 2008, when we had an amazing offer from Chelsea for Franck Ribery," he told Kicker. "From that day on, the whole football world knew - nobody can buy a Bayern Munich player against Bayern Munich's will.
"I want to assume that Robert is 100% going to play for Bayern next season."
Lewandowski has maintained his impressive goalscoring rate at Bayern by notching 32 goals in 37 appearances this season.