SYDNEY Swans veteran Adam Goodes has been ruled out of Friday's match against Carlton at the SCG after aggravating a knee injury at the weekend.

Scans on Monday revealed the Swans' star utility had damaged a posterior cruciate ligament in his right knee during Saturday's upset loss to Port Adelaide.

While it is not the same ligament he ruptured in last year's grand final, it had caused Goodes some issues in a pre-season clash with Port in Adelaide.

But coach John Longmire is hopeful the 33-year-old will only miss a single game.

"Hopefully it's just a one-week injury, but we'll have to wait and see what he's like next week," Longmire told reporters on Monday.

"It could've been a lot worse."

The premiership-winning mentor said the decision to substitute Goodes off at three-quarter time wasn't taken lightly, given the game was still in the balance.

"But clearly he was sore and restricted by it, therefore he misses - I'm hoping - only the one week," he said.

The mid-season injury adds to a long list of Swans casualties, which includes eight premiership players with more than 1100 games of combined experience.

While the likes of Lewis Roberts-Thomson (knee) and Rhyce Shaw (abdomen) remain long-term prospects, Shane Mumford (face), Lewis Jetta (shin) and Sam Reid (quad) are still weeks away from returning.

Longmire confirmed both Jetta and Reid won't play this weekend, with Andrejs Everitt (ankle soreness) the only name on the injury list with a chance for a spot in Friday's squad.

"But that's what happens - you've got to deal with it," he said.

"It's just everyone has their turn and when it's your turn you've just got to make sure you play well and get the players in the team that need to contribute on a weekly basis.

"I'm confident that what we'll be able to do, is lift our performance this week and make sure we put in a really strong performance against Carlton who have been a bit unlucky against some of the teams that have played really good football this year."