Agents of other high-profile RFAs are waiting for Marner to sign first to set the market, a source told The Athletic's Joe Smith.
Marner is one of several young RFAs coming out of entry-level contracts this offseason, along with fellow stars Brayden Point, Mikko Rantanen Brock Boeser, Patrik Laine, and Matthew Tkachuk, among others.
Coming off a 94-point campaign, Marner could be in line to become the highest-paid member of this year's RFA class, but Toronto's salary cap constraints have prolonged the process. That said, the 22-year-old did state he wants to be with the club for training camp in September.
Contract negotiations can drag into the regular season and cost players games, as was the case last year with Leafs winger William Nylander, who signed on the Dec. 1 deadline - minutes before he would have been forced to sit out the entire 2018-19 campaign.
Negotiations that leak into the regular-season schedule also cause signing players' first-year cap hits to be prorated, creating additional financial headaches for teams up against the salary cap.