Koby Stevens has already played his last game for the year.

Unfortunately, due to concussion, Stevens will not be able to make a comeback this season.

The 26 year-old suffered a knock to the head in the first game of the season as he held star Lion Dayne Zorko to 14 disposals. There were no signs of concussion following the game, however Stevens was dropped after St Kilda's round two clash against the Roos.

In round three, Stevens didn't play any football as he served as the emergency for the senior squad.

In the lead-up to the round four match against Geelong, Stevens reported symptoms consistent with concussion and was diagnosed as such.

“Koby is not where he’d want to be,” Saints coach Alan Richardson told reporters on Friday.

“It’s been a tough time for Koby. He’s still  a young man and he’s still got potentially a bit of footy ahead of him, but this last head knock has really shaken him up a bit and he’s still unable to exercise at any sort of level.

“We just have to leave that in the hands of the doctors and make sure we support him and that’s certainly what we’re doing.

“Our welfare staff and our medical staff are making sure he gets what he needs.”

St Kilda have already had a horror start to the season and the bad news just keeps on piling on.