I think with a healthy Westbrook/Durant anything less than the Finals is a disappointment..I think if they kept Brooks, they would have to win the championship for KD to resign.
With Billy Donovan, there is a little bit of forgiveness in the players eyes....as long as it looks to them as the new coaching style has some serious potential (and with KD/Westbrook healthy, I could coach them to a good record and show "potential")
If Donovan is so bad they miss the playoffs, then that's pretty bad