The worry with concussions and traumatic brain injuries is that with each one, the next one comes easier and the effects last longer. Jake Muzzin could, and likely should, be out of the lineup for quite awhile for his own safety. We all wish Jake a full and speedy recovery. It was a scary incident that nobody wants to see.
On the ice, the Leafs lose a veteran top 4 defenseman, and one of the few players on the roster with a Stanley Cup ring. If Muzzin is out long term, they'll need to fill that hole in the lineup. Without Muzzin, the Leafs have Morgan Rielly, Rasmus Sandin and Travis Dermott on the left, and T.J. Brodie, Justin Holl, Timothy Liljegren and the newly acquired Ilya Lyubushkin on the right. That's 7 defencemen who can play in the NHL, but it's not a D corps that's particularly strong or deep enough to make noise in the playoffs.
The name Mark Giordano has been in trade talks all year, and it's been reported he would accept a trade to Toronto. If Muzzin is expected to be an LTIR candidate, adding Giordano would go a long way towards shoring up the left side for the Leafs in the absence of Jake Muzzin.
The former Norris trophy winner has worn the «C» in both Calgary and Seattle. He's big, he defends well, moves bodies in front of the net and can chip in on the scoresheet as well. As a pure rental, with salary retention he could easily fit into Toronto's cap structure with Muzzin sidelined.
The D pairings would then likely become:
Rielly-Brodie
Giordano-Liljegren
Sandin-Lyubushkin
(Dermott, Holl as extras)
This gives each pairing a good balance of offensive ability, physical play, defensive play and as a bonus, Liljegren gets a veteran mentor to play alongside in the playoffs if Muzzin misses more time than expected.
The cost of acquiring Giordano is likely to be a 1st or second round pick, plus a mid round pick or a "B" level prospect for salary retention. They could even swap a future late round pick with a third team for some extra retention if they have another move up their sleeve.
Hopefully we have an update on Muzzin's status soon, but if that update isn't good news, Mark Giordano should jump to the top of Kyle Dubas' wish list.