TOUGH St Kilda midfielder Koby Stevens has been ruled out for the rest of the season as he battles concussion.
Stevens, 26, suffered a head knock in round one against Brisbane, when he held star Lion Dayne Zorko to 14 disposals.
He didn't report any signs of being concussed after that game and was dropped following the round two loss to North Melbourne. Stevens didn't play any football the next weekend, instead serving as the senior side's carryover emergency.
In the lead-up to the round four match against Geelong, Stevens reported symptoms consistent with concussion and was diagnosed as such.
"He won't be back before the end of the season," Saints coach Alan Richardson told reporters at RSEA Park on Friday.
Richardson's uncertainty about the timeframe for Stevens' return painted an ominous picture about his future.
"Koby is not where he'd want to be. It's been a tough time for Koby," Richardson said.
"He's still a young man. He's still got, potentially, a bit of footy in front of him.
"This last head knock has really shaken him up a bit and so he still isn't able to exercise at any sort of levels, so it's really uncertain as to when he'll be back.
"We just have to leave that in the hands of the doctors and make sure we support him, and that's what we're doing from a welfare perspective."
Stevens is with his third club since being drafted by West Coast at pick No.23 in 2009 NAB AFL Draft, before being traded to the Western Bulldogs at the end of 2012.
He spent four seasons there before moving to the Saints in 2016.
Stevens suffered from a bout of salmonella in his pre-season at the club, which caused him to lose eight kilograms and the hard nut held serious fears throughout that period.
He managed 15 games last year.
"All I was worried about, at the time, was surviving it really," Stevens told AFL.com.au last November.
"I was pretty crook. I've never been so sick in my life."
Luck was on his side in August that year when a timely email helped Stevens avoid stepping into Brighton Beach for recovery, when it had become infested by flesh-eating lice.
The following week, Stevens was concussed and suffered an ear injury in a head clash with Melbourne onballer Angus Brayshaw.
Stevens didn't miss a game but it later emerged he played through the end of the season with a torn adductor.
He isn't the only Saint to have had a torrid recent run with concussion. Paddy McCartin has suffered the injury seven times since the start of 2014, while defender Sean Dempster retired early last year because of fears it could affect his future health.
