Not much teeth to the offersheet boogeyman.
Chris Johnson said Marner has definitely talked to teams about a 3 year offersheet, likely looking for that high qualifying offer number in the final year, but an AVG below ~10.5M (and thus two 1sts + 2nd + 3rd compensation) to try to entice the Leafs to match.
However, San Jose, Chicago, Colorado, Columbus, Dallas, NJD, Pittsburgh, Washington, Arizona, Buffalo, Minnesota, and Philly have all traded one of their first three picks next draft and are inelligible for an offersheet of that calibre.
Beyond that, only two teams in the league have more than 9M in capspace... Ottawa and Winnipeg. Winnipeg needs to sign Laine/Connor, so they're out. That leaves Ottawa, where: 1) Melnyk is cheap and won't be paying a ~9-10M offersheet with a big qualifying offer # in year three; and 2) Ottawa sucks and is one of the few teams where two 1sts + 2nd + 3rd could actually be good compensation.
Marner's only leverage is sitting out the season, which is a nuclear option that hurts him a ton. If no team is giving him the big payday today, they're not giving it to him after he sits out a year. Plus he'd miss out on a year of his prime earnings.