You have no way of knowing for certain whether they will fire him or not. We lost a coach once in the middle of preseason, signed a guy that most here hated that happened to go on a 5 year winning streak.
We took a team that was on Path A for 5 years under Allegri to a new coach and new philosophy to go on Path B and happened to hand him a shitty midfield. We still one the league, pretty sure early on we knew CL was out b/c of the holes the SARRI DID NOT CREATE HIMSELF.
Either give Sarri the players he needs to make his system work or find a new coach who's system is more closely aligned with the players we have/or are getting.