ADELAIDE, AUSTRALIA - AUGUST 04: Tom Jonas of Port Adelaide during the round 20 AFL match between the Adelaide Crows and the Port Adelaide Power at Adelaide Oval on August 4, 2018 in Adelaide, Australia. (Photo by Mark Brake/Getty Images)

Port Adelaide captain Tom Jonas might've already played his final game for the Power, with the club revealing on Friday that the veteran defender will be sidelined for up to three weeks with a calf injury.

Jonas sustained the setback in the final minutes of Port Adelaide's main training session on Thursday - just two days out from the South Australian side's Qualifying Final against Brisbane at the Gabba.

The 32-year-ol underwent scans later that evening and was ruled out of Saturday's clash with the Lions due to injury, with the Power confirming on Friday that Jonas will be sidelined for the short term.

In a short statement made by Port Adelaide, the club confirmed Jonas will require between two and three weeks in recovery before returning from the untimely calf strain.

"Port Adelaide captain Tom Jonas will be unavailable for selection in the short term after scans confirmed he had suffered a calf strain," the injury update read.

"The 32-year-old hurt his left calf at training on Thursday.

"The injury will keep Jonas sidelined for two to three weeks."

The setback could spell an abrupt end to Jonas' AFL career, with the key defender having already announced this season would be his last in the competition.

Jonas announced his retirement in August, flagging the club's premiership run would cover his final month in the game.

While also battling with spots at selection, Jonas' calf injury places further doubt over his chances of returning to the field in 2023.

Jonas has played 216 games for Port Adelaide since 2011 and was appointed as club captain from the 2019 season.