Gun Collingwood defender Tom Langdon faces an uncertain future due to a lingering knee injury.

According toย AFL Media'sย Damian Barrett, the 25-year old has no time frame on when he will return.

Langdon hasn't played since round nine last year and Collingwood coach Nathan Buckley admitted his pathway back was unclear.

"The outcome there is still not clear on what his body is going to allow him to do," Buckley told AFL Media.

"And, you know, when you've gone along the track โ€“ I think it is round eight was the last game that he played โ€“ that's not been a short amount of time.

"So we need a fair bit to go his way, but we're not giving up on it and neither is he, clearly, because he loves playing. He loves being involved in the group as well."

Asked if the injury could cause Langdon to consider retirement, Buckley responded: "Well, that's been part of the discussion and even Tom himself working it out.

"With the revelation of Dermie (Hawthorn great Dermott Brereton, now battling with a serious back ailment), and his back and the rigours that you put your body through in a professional existence and what that actually leaves you.

"What are the remnants of your professional career that actually stay with you for the rest of your life?

"So that is something that Tom has considered and that we are conscious of.

"So I think, given all of those discussions and possible repercussions and realities, you know, we're still going down the path because we feel, on balance, that Langers can still get back and play the game he loves, in an environment that he loves.

"So that's our endeavour and we're working towards that."

Langdon was one of the Pies' best in the 2018 grand final and he impressed again in the first nine matches of last year.

After getting indefinitely sidelined due to chronic cartilage damage to his right knee, the backman eventually underwent season-ending knee injury.

Buckley said Langdon is back on the park and running to test his knee out, but faces significant challenges ahead.

"Langers has come out and has done a few runs outside, he's working through that knee," Buckley said.

"And it's a very challenging position for a young professional to be in, especially a guy who's shown that he's more than capable at the level โ€“ some of his performances over the last couple of years have been exceptional, especially in big games.

"He's a balanced kid, Langers. He doesn't have all his eggs in one basket, so he's been a sort of been able to manage himself through this process.