It might of been his injury but he did look the slowest man out there last week.
Scott West's career ended in a similar way, barely missed a game in his career until a niggling injury just continued to the point where he couldn't play.
I fear that Johnno will end up the same way. Perhaps we need to handle him with kid gloves, ease him back in at Williamstown until his body stands up. It's clear he isn't pulling up well at AFL level after the interuptions and injuries he's had.