Munster's contract expires in 2027, the likely end of Craig Bellamy's Storm tenure, but Melbourne has not named a successor.
Munster told The Daily Telegraph there was "no real inkling or guarantee" about who would take over.
He has said he would like to stay at Melbourne while Bellamy coaches and is preparing to represent the Kangaroos at the upcoming World Cup.
Munster is likely to test free agency from November 1 after Melbourne offered about $750,000 for next season.
He currently earns around $1 million annually.
The offer comes as Munster's form has dipped slightly and the Storm face a tighter salary cap.
His management says he has no reason to accept a pay cut.
"I'm getting lowballed by everyone," Munster said.
He told the newspaper he remains undecided about his future.
"I'm not ruling out leaving," Munster said.