They should just make a new team of guys who retire and then try comebacks (some have actually been successful):
Forwards: Jagr, Fleury, Modano (rumoured)
Defense: Chelios (I think I heard a few years ago that he wanted to try)
Chelios has only missed a few seasons. You're forgetting a bunch of guys who have tried for the Leafs in the not so distant past: Thomas, Allison, O'Neill.
I was really rooting for Fleury in his attempted come back, thought he might actually have a decent chance.
Not sure why anyone would want Yashin. Probably still has some skill, but would have a negative mentorship impact and would have to overpay him to compete with the money he could earn in the KHL.
Is there any chance Yashin has matured? Sometimes, people actually do change. If so, I see Yashin as a decent top-nine with some scoring potential. A right handed shot on PP, and maybe 15-20 goals at best. At worst, a locker room cancer creating conflicts and ruining the team. A high risk, low reward signing. How about Phoenix? Does he golf?