How much information can Elias get from the doctors involved?
Regardless of if he can play next year you don't want to take the PR hit of non-tendering him so you try and work a deal with his agent that protects the team as much as possible. If they want to force arbitration on you then you are in a poor position since you would ideally like to cut his guaranteed money by more than 20%. Push comes to shove you go to arbitration with the 20% cut and are prepared to cut him in ST if he can't play and is being unreasonable about working toward an equitable solution for both sides.
Mancini doesn't seem to be the type that would be hard to deal with so I expect them to come up with an agreement that's good for both sides.