if Lupul is deemed healthy, then he's absolutely getting buried on the Marlies, no question.

Unlike with Robidas, now all salary above $1 million or so per AHL player counts against the NHL team cap.
Plus Lupul has a 14 team approved trade list, making him harder to trade.
Retaining salary wouldn't help, paying a team with an internal budget would be expensive in terms of picks/prospects, and all this leads to trading JVR on very short notice for whatever doesn't return salary.

BUT Lupul is going to be a good boy, he's out of shape and not ready to play if the Leafs are forced into letting him play. So he'll shut up and not challenge the physical's results with independent doctors.

The one remaining risk is if Lou Lamiorello gets spanked by the other owners like they did with the Kovalchuk contract. Rogers has substantial influence with the core NHL executive, but even they take orders from the core group of old owners.

If he does pass, he doesn't play for the Leafs. And he's not tradable. So it's about 4.1 of cap hit with when he is sent to the Marlies (and doesn't play there either). But Lupul has to get the NHLPA involved and invoke his right for "another opinion:. If he does goes the "union route", it really doesn't matter what Lupul says.
And Lou certainly isn't going to spanked by the NHL or other owners. Other clubs might want cap help in future years,(like Detroit this year) so why upset the system. And even teams like Arizona has benefitted by trading for guys with LTIRs and therefore reached the cap floor without actually spending real $$$$. I don't Rogers/Lou or the Leafs have any influence on what other teams think or do. Teams worry about their business and team, and if it meant screwing the Leafs they might do. But most teams will use the LTIR (and why shouldn't they ) to their cap benefit at some time.
As the roster shows, Leafs have cap space even with Lupul on the roster and even more if he's a Marlie, Leafs don't have to trade another to cap compliant.