i understand your concern, but if his neck turns out to not be a chronic problem can you say boldy or rossi have shown they will be that caliber of player? I dont think so. We also have prospects (beckman, marat) that are rising fast to the caliber of prospect that those two are at now. So it makes the deal easier for me. Fiala is probably gone after this year anyways barring a shuffle on the roster. So in all honesty this seems like a fair hockey trade.
A lot of ifs here that seem to be ignoring cap implications. I am by no means expecting Boldy or Rossi to be the equal of a healthy Eichel. Fiala is a 24 yo 1st line player with one year of team control left after this one. Still not close to a healthy Eichel, but he's worth something. B + R are on ELC's. That's worth something. Eichel is being paid 10M. That matters.
If MN were assured that they were getting a pre 2020 Eichel with no neck problems you'd do Fiala + B/R + Greenway + quite easily. The problem here is what happens if Eichel ends have chronic neck problems that cause to either sit out, or play at a lower level than you are accustomed to seeing? Then you have added a liability to the team that not only has cost you some good players, but is killing you cap wise. Bottom line is that 2019 Eichel is very good, 2020 Eichel was not, and post surgery Eichel might be a declining asset.
I don't agree that Fiala is gone after this year. Why would they do that? If they are prepared to pay 10M long term for a (potentially) damaged C, then why not pay Fiala 7- 7.5M instead, especially if Rossi is showing signs, and Marat decides to come over after having a strong KHL season?
Until we know how Eichel will heal up and withstand the rigors of the NHL post surgery it's near impossible to say what is the right value for him. The only thing I can say for sure is that KA has goofed up this whole process. He should have quietly let Eichel have the ADR back in June, then moved him for the best possible value as soon as he started skating. He would've been gone by now, and the Sabres might've had a player or two to show for it, as well as a prospect/pick or two, whereas now they have a 10M hole in their bottom line that is sapping the morale and goodwill of the team.