THREE injury-hit seasons have taken their toll on Richmond's Chris Knights, with the half-forward to retire at the end of this season.

It's a disappointing end for the 28-year-old, who never had the opportunity to fully embrace his shift to Punt Road from Adelaide after the competition's first-ever free agency move in 2012.

The former Crow was cut down by a terrible knee injury just five games into his career as a Tiger in 2013, with complications and then persistent muscle injuries limiting him to just one more AFL game.

"It's a really sad ending for Chris," Richmond football manager Dan Richardson told the club website.

"He has had horrible luck with injuries since he arrived at the club, and it's unfair for him to have to bow out in this fashion.

"While he spent a lot of time in rehab, he was a fine role model for the playing group with his determination and professionalism to overcome a number of significant injuries.

"He will be rightly remembered as highly-talented player who stopped at nothing to get the best out of himself."

Knights made his AFL return in round three this season against the Brisbane Lions but broke down with a hamstring injury that needed surgery and cost him 10 weeks.

He has been in and out of the VFL since, with a quad injury interrupting his ability to string games together.

Knights played 96 games for the Crows before returning to his home state of Victoria to play for the Tigers.

An emotional Knights told his teammates on Thursday morning and spoke of how grateful he was for the support and care he was given throughout his difficult time as a Tiger.
"It's been a tough three years here and no doubt you guys are aware with injuries I just haven't been able to have a good run at it," Knights said.

"I couldn't have got through it without the help of everyone in this room, especially the players and the support staff."

Knights' announcement follows on from the news Chris Newman will retire at the season's end, and Nathan Foley's decision to immediately hang up the boots.