During his time with the UFC, Griffin has put on many memorable performances and accumulated a larger fan following than most fighters could even dream of.
He has been such a consistent presence in the UFC for so long now, that picturing the promotion without him seems strange.
But, all good things must come to an end.
At UFC 134, Griffin was knocked out by Mauricio Rua in under two minutes, putting him at 2-3 in his past five fights.
Indeed, it's been while since we've seen Griffin put on a performance like he gave against Jackson to win the light heavyweight strap and it seems like the former champ is on the decline.
Here's six reasons Forrest Griffin should be considering retirement right now...