However, Martinez has been restricted to just 10 starts in all competitions in 2019-20 and recently entered the final 12 months of his contract.
"We know that he would like to leave the club with a suitable offer," Rummenigge told AZ.
"We wouldn't put any obstacles in his way because he was always a good player and a reliable, serious person. We will always try to find a solution that suits the player."
Rummenigge also reiterated on Wednesday that fellow midfielder Thiago Alcantara, strongly linked with Liverpool, will only be allowed to leave if his valuation is met.
Bayern are also in talks with versatile defender David Alaba over a new contract, while loanee Philippe Coutinho will return to Barcelona later this month.