Mitch Marner was on the case.

Not long after his close friend, Jake Muzzin, left the Oct. 17 loss against Arizona with an apparent neck injury, Marner let the world in on the potential severity of it with his comments: “Obviously for him it’s just making sure that, if he does come back and play this year, or whatever happens, just make sure that he’s going to be able to do whatever he wants to do the rest of his life and enjoy the time with his family, his kids.”

It was one of those foreshadowing quotes that spoke volumes. A player’s life and well-being after hockey is always of paramount importance. Fast forward to this week, nearly a month later, when the Maple Leafs announced that Muzzin would be out for the foreseeable future with a cervical spine injury, to be re-evaluated next in late February before the March 3 trade deadline.

For Toronto, Muzzin’s injury is probably the best outcome in a worst-case scenario. They are down a blueliner who was acquired and paid to be a big part of a playoff run, but injuries have mounted, and at least now they have clarity and flexibility.

GM Kyle Dubas said Monday that in the short-term, the Leafs will provide no shortage of opportunity for young defensemen Rasmus Sandin and Timothy Liljegren to step up and seize the moment. In the long-term, it seems like a foregone conclusion that the Leafs will use all of Muzzin’s $5.625 million LTIR space to boost a back end that many viewed as already in need of reinforcement when Muzzin was healthy.

This is a burn-the-boats type of season in Toronto, where no stone should be left unturned. It’s now or never to make a dent in the Stanley Cup playoffs for this core.

So, who is available on the blueline? As Senators GM Pierre Dorion noted on Tuesday, it is the toughest position to trade for in the NHL.

Given the list below, Dubas may have to stray from his preference of not acquiring rental players, since there are seemingly very few defensemen with term available. Teams that have steady defensemen are in the business of hanging onto them, unless there is a significant premium paid. And it’s not as if Dubas, in the last year of his contract without an extension, should be thinking much beyond this season anyway.