PROMISING Brisbane Lions defender Sam Skinner requires a third reconstruction after rupturing the anterior cruciate ligament in his right knee in the Lions' NEAFL win over Greater Western Sydney on Saturday.

It follows on from two ACL repairs on his left knee – the first in 2015, and the second last year after he reinjured it at training just hours after being told he would make his AFL debut that weekend.

Skinner, 20, was set to play against Port Adelaide in the round 18 match in 2016, and had even told his family he'd been picked in the senior side for the first time.

However, some extra marking practice at training saw him land awkwardly and wrench the repaired knee, with his debut suddenly on hold and another season-ending operation scheduled.

He recovered from that second reconstruction to play his first and only AFL game in round 19 against West Coast this year, in which he kicked two goals.

"It's devastating for Sam," Lions captain Dayne Beams said on Tuesday.

"He's heartbroken, and a lot of our hearts broke with him when we heard the news.

"He's such a well-respected guy around our footy club.

"He's been through a number of challenges over his short career, but I know Sam personally and have a really good relationship with him, and what I can say about him is he's one of the most resilient people I've ever come across in footy.

"He's got another nine to 12 months ahead of him of rehab, and he's going to have his ups and downs, but what he's got is a playing group and our footy staff that are supporting him all the way."

Skinner was drafted with the Lions' third pick overall (No.47) in the 2015 NAB AFL Draft.