SCANS have confirmed Carlton defender Sam Rowe has a ruptured anterior cruciate ligament that will end his 2017 season.

Rowe, 29, injured his right knee in the Blues' loss to Fremantle at Domain Stadium on Sunday, with the Blues confirming on Monday the key defender would require a knee reconstruction. 

Rowe hyperextended his knee in the first quarter of Sunday's game when Freo captain Nat Fyfe attempted a smother.  

He came from the ground and was assessed by the Blues' medical team, with tests at that time understood to have found Rowe's ACL was intact.

Rowe returned to the ground late in the opening term with his knee strapped, but his right leg buckled in a marking contest soon after and he took no further part in the game. 

Carlton football manager Andrew McKay explained how Rowe had been injured on Monday afternoon when he spoke to Melbourne radio station SEN.

"Sam went to kick the ball and Nat Fyfe went to smother it. There was a slight hyperextension of Sam's leg there. He was on the ground for another six or so minutes after that because he felt a bit of discomfort," McKay said.

"He got assessed by the medicos – both doctor and physio – and certainly any ACL damage was ruled out. They strapped him up, he ran around the boundary line, cutting different angles, changing direction and the knee stood up really well, so they ruled him fit to go back on the ground.

"He went back on the ground a little while later and he was out there for five minutes. In a marking contest, his planted foot, that leg twisted and that was a different action to the first action. That's what's caused the damage."

There was some consideration given to LARS surgery but McKay said that looks unlikely.

"He'll see a specialist in the next 24 hours but we spoke about that with Sam and Sam's leaning towards the traditional route," he said.

"If we went LARS, then he'd still miss this season. He'd fit more of pre-season in but if we go down the traditional track, he'd still be right for round one next year.

"Without confirming, it's looking more likely to go down that track."

Rowe has been a regular senior player for Carlton since the start of the 2014 season, and had not missed a game this season before his injury.

Selected by the Blues as a mature-age recruit in the 2011 NAB AFL Draft, Rowe was diagnosed with testicular cancer in his first season at Ikon Park but made a full recovery, returning to make his debut in round two, 2013. 

Rowe has played 82 games for Carlton and finished fifth in the club's 2014 best and fairest award and equal sixth last year. 

He turns 30 in November and while his contract expires at the end of the season, McKay said that situation would be addressed in the "not-too-distant future".

Forgotten Blue Liam Jones has been playing as a backman in the VFL and McKay said the former Dog has been in the best players for the last five games, and is a chance to replace Rowe against North Melbourne at Etihad Stadium next Sunday.