SYDNEY Swans coach John Longmire says star forward Lance Franklin has been ruled out of football for the rest of 2015.

The three-time Coleman medallist took indefinite leave from the club last week to seek treatment for an ongoing mental health issue, and Longmire told media on Monday that Franklin would not be selected again this year.

"Lance won't be playing for the rest of the season. We're mindful of his mental health issue and it's something that needs to be addressed," Longmire said.

"That's his main priority, to get that right, so footy is not on the agenda for Lance for the rest of the season."

Full match coverage: Fremantle v Sydney Swans

In a further blow to the Swans' forward line stocks, Sam Reid has also been ruled out for the season after tearing his hamstring against Fremantle on Saturday.

Longmire said that the dynamic 23-year-old had suffered a significant injury that will sideline him for over a month.

Reid has been in the best form of his season over the past month but now joins Franklin, co-captain Kieren Jack and midfielder Luke Parker on a star-studded injury list.

It will leave the Swans' attack undermanned with Kurt Tippett, Adam Goodes and Dean Towers likely to be Longmire's tall options up forward.

In better news, Nick Smith (hamstring) is a chance to return form injury to face the Kangaroos after missing the past two games, with the defender likely to train lightly on Tuesday, before attempting to rove his fitness at training on Thursday.

Sam Reid has been subbed off after this injury. #AFLFinals http://t.co/L8wOXa5Af8 — #AFLFinals (@AFL) September 12, 2015

Parker (leg) and Jack (knee) are highly unlikely to play in Saturday night's semi-final.

"Luke Parker is walking past my office and doing cartwheels but he'd have to do a pretty good set of cartwheels for the rest of the week to be able to play, so we'll have to wait and see," Longmire said.

"We certainly won't risk him but he's actually coming along pretty well so that's a good sign."

The Swans might not be able to call on some of their biggest stars for their semi-final clash with North Melbourne at ANZ Stadium on Saturday night, but Longmire preferred to keep the focus on the players who will be fit to take on the Kangaroos.

"We know we've got some quality names out, you can't deny that, but when we put the names up on the match committee board we look at the players we've got rather than the ones that we haven't," Longmire said.

"We were pleased with a lot of the players that played on the weekend. We thought they really contributed but we need to go again this week.

"Whether they're experienced players or younger kids coming in and playing their first or second final, they need to perform well."