By "long term" I would sign him for his last year of RFA status and his first two years as a UFA, discounted to reflect that he has had a problem staying healthy. Three years at $3.5M to 4$M per year
He is a 25 year old dman who played top line minutes most of the year finishing with the third highest TOI on the team. Where Z is a great PP specialist, Murray is a huge part of the PK and generally plays top unit minutes with Jones. 29 points in 56 games is no joke for a dman who is d first guy. He's the best first pass guy we have on the back end and he's still getting better. Injuries suck, but trading a dman like that at that age seems highly stupid to me.
If you're set on trading a guy on the back end it should probably be Nuti. 3 more years at $2.7 mil is a contract and a body we really don't need. He's not a top 4 guy, Murray is. That's where the distinction has to be.
The only logic in moving Murray now is if you think you can get a really good return AND you think Gavrikov is a top 4 dman right now. And even then, I still wouldn't do it.