MELBOURNE, AUSTRALIA - JULY 08: Koby Stevens of the Saints kicks the ball during the round 16 AFL match between the St Kilda Saints and the Richmond Tigers at Etihad Stadium on July 8, 2017 in Melbourne, Australia. (Photo by Michael Dodge/Getty Images)

St. Kilda midfielder Koby Stevens has been forced into retirement, after being unable to recover from persistent concussion symptoms.

The 27-year-old, who played 91 games for West Coast, the Western Bulldogs and St. Kilda had not played since round two against North Melbourne, following his concussion suffered in the opening round against Brisbane.

According to theage.com.au, Stevens told him teammates and coaches on Monday.

“I was pretty good in the early days, but we had a scan result come back that suggested that I did have changes to my brain,” Stevens told Fox Footy back in May.

“I was pretty hurt as it was pretty tough to take. I’ve taken hits, come back from them strong, but to have someone say there’s been changes to my brain and they can’t really tell you what they are, they’re just there, it’s tough.”

Stevens was drafted at pick 23 by the Eagles in 2009 and played 11 games before being traded to the Bulldogs at the end of the 2012 season.

Stevens was on the list in the Bulldogs’ premiership year of 2016, playing in their VFL Grand Final winning side.

He was traded to St. Kilda in October of that year, and played 17 games in his time at the Saints.