Sydney have ruled out star forward Lance Franklin from Saturday’s AFL qualifying final against Fremantle as the star deals with an “ongoing mental health condition”.

The Swans don’t know when Franklin will return to football as he deals with his illness.

Sydney football manager Tom Harley said Franklin had the club’s full support.

“Our first priority is looking after Lance’s health,” Harley said.

“The timeframe on his return is unclear at this stage.

“He will certainly miss this week’s match and we will continue to monitor his condition.”

The Swans announced the bombshell news on Tuesday afternoon, four days before their crunch qualifying final in Perth against Fremantle.

Franklin, in his second season at Sydney, has been struggling to produce his best in recent weeks owing to a back injury.

The two-time premiership winner with Hawthorn was Sydney’s best in their grand final defeat to the Hawks last year.

Franklin joins key men Kieren Jack and Luke Parker on the sidelines as they attempt to secure an unlikely home preliminary final.

Jack strained a medial ligament in the Swans’ round 23 win over Gold Coast, while Parker is still recovering from a broken leg.