Justin Caines has confirmed that Cameron Munster turned down a two-year Melbourne Storm offer worth about $750,000 per season, a reduction of roughly $350,000.
The 32-year-old has one year remaining on his contract, which runs until the end of 2027, and could negotiate with rival clubs from November 1.
Munster, a two-time premiership winner, has not ruled out moving to Sydney but says he is not committed to leaving Melbourne.
"I'm getting lowballed everywhere. It's the first I've heard of it," Munster said after joining the Kangaroos camp with teammate Harry Grant.
"But I guess my manager's just doing a job, trying to see what's out there. I'm not saying I'm leaving. I love Melbourne (but) if I get paid, he gets paid.
"I don't know about that. I don't know where they're going with that. I think that's just a bit of speculation hype."
Several high-profile players, including Nathan Cleary and Latrell Mitchell, are also set to become available to negotiate from November 1.