I don't think he could win against Duffee at this point.
Mir is 36. The current champ is 38 and the guy Mir just lost to is 41. If Mir retires, it would probably not be due to age. He said before the fight he wants to go another 4, 5 maybe 10 (!) years. If he wants to continue to fight and make money, he can probably still beat 75% of the bums in the UFC heavyweight division. He should really consider getting in better shape though if he wants to keep going.
Mir is 36. The current champ is 38 and the guy Mir just lost to is 41. If Mir retires, it would probably not be due to age. He said before the fight he wants to go another 4, 5 maybe 10 (!) years. If he wants to continue to fight and make money, he can probably still beat 75% of the bums in the UFC heavyweight division. He should really consider getting in better shape though if he wants to keep going.