I'd imagine they're looking for point producing C's given that they have Couturier/Cates/Poehling as 3/4 of their C group and they are all defense first, low offense. Frost is their only offense first C and his point production isn't playoff top 6C caliber. I would think they're looking for a 1C and even a 2C to replace Cates and Frost. Couturier isn't going anywhere and Poehling is a perfect 4C - no need to replace him.
I guess it really depends on what they think of their team, and where they are headed. Are they that C away from competing? Are they retooling, rebuilding? I like your Cates idea, but he's only 25 years old, so in anything but a rebuild, they likely don't move him either.
The ship has sailed on Kastelic. Boston just signed him to a deal that looks like a steal for what he provides at 4C. Any acquisition would have to be an overpay and the Leafs would be foolish to overpay for a 4C.
I do like when people bring him up on this board - I received a ton of pushback here when I proposed Timmins for Kastelic in the summer of 2023.
As far as Krebs goes - I don't see it. Low offense, middling defense. He's never scored 20 goals in a season, going back to junior. He is physical though which I do like.
For sure Kastelic is a long-shot, and I said so in my first posting on him a few days ago. But a phone call is cheap, and if they throw in the towel, they might just be thinking of an all out rebuild. Long shot at best.
Krebs... I think the hope there, is that a change of scenery brings out more in the guy. Buffalo has been terrible at developing players... he plays most often with Lafferty and Malenstyn. Lafferty is a black hole offensively, and has 4 points on the season. I think he'll go somewhere else, and be a 0.5 PPG guy, mostly a setup guy, and some physicality, being decent in the dot. Remember, he's just 23 years old. He's also being started 64% in the dzone, so heavy dzone usage, on a terrible defensive team... I don't think the numbers look terrible in those circumstances. A setup guy is ok as a C, as we've got a number of shooters... McMann, Robertson...