The Hammers have been consistently linked with a move for the former Fiorentina forward.
However, Rummenigge insists the player will be going nowhere.
"Toni's future is at Bayern Munich 100%," Rummenigge is quoted as saying by Goal.com Italia.
"After his injury he's been training under Louis van Gaal and he's left a very good impression on our coach. Soon he will be re-integrated into our squad and he will be a fundamental player for us."