I agree. There was one game towards the end where he got subbed off after being put on toast by a speedy winger and just sat on the bench looking as though his world had ended. He knew right there that he could no longer hack it at that level. Much as it pains me to say it, as I absolutely loved the guy, but it was time for him either to move on or become a bit-part player, perhaps with a move to coaching on the side. Or, as he did, get regular game time in a slower league.
What we didn't do was replace him adequately.