SYDNEY captain Callum Mills has been ruled out of the 2024 Toyota AFL Grand Final.

Mills had a fitness test at the SCG on Wednesday morning and while he said he was "feeling good" after the session, the club made a call a few hours later to rule him out of the match against Brisbane at the MCG on Saturday afternoon.

"Mills trained this morning and after taking everything into consideration, a joint decision was made by the club's medical staff and the coaches to rule him out," the club said in a short statement.

John Longmire and Callum Mills at Sydney training at the SCG on Wednesday, September 25. Picture: Phil Hillyard

Mills missed the 36-point preliminary final win over Port Adelaide due to a hamstring issue but had built his training load over the past week to put himself in contention to face the Lions.

"(I) trained 100 per cent," Mills told reporters outside the SCG after the fitness test on Wednesday morning.

"Hopefully (I'll play). It's over to 'Horse' (coach John Longmire) now. But got through training and feel good. Just had to train hard and hopefully, that’s enough.

Callum Mills and Harry Cunningham at Sydney training at the SCG on Wednesday, September 25. Picture: Phil Hillyard

"I’ve just been worried about the team and making sure we’re in the best shape to play well in a granny."

The versatile Robbie Fox appears likely to hold his spot as a result of Mills's absence.

Logan McDonald also trained fully at the SCG and is expected to face Chris Fagan's side after being subbed out of the preliminary final against the Power.

Mills has endured a frustrating 2024 campaign after undergoing major shoulder surgery last September after damaging his rotator cuff at a post-season event.

Callum Mills at Sydney training at the SCG on Wednesday, September 25. Picture: Phil Hillyard

The 2022 All-Australian then suffered a calf injury in April and didn't return until round 18. He then missed the following week due to soreness, played the next six games before the hamstring strain in semi-final week.

If Mills was picked to play in the decider, it would have been 18 days between the injury and the game. He has played just one game, the qualifying final against Greater Western Sydney, in the past month.

In the aftermath of the loss to Geelong in the Grand Final two years ago, Longmire labelled the decision to pick Sam Reid a mistake after the tall forward injured his adductor in the preliminary final, before being subbed out of the Grand Final just after half-time.

Callum Mills at Sydney training at the SCG on Wednesday, September 25. Picture: Phil Hillyard

The 53-year-old, who has now qualified for a fifth decider in 14 seasons at the helm of the Swans, said on Tuesday the club had learned from that decision, although Ted Richards proved a decade earlier that some players can rise to the occasion after entering under an injury cloud.

"You always learn and one of those things is to train at 100 per cent, get through training and train flat out. That's one of the things you learn," Longmire said said.

"That [Sam Reid] is one of the stories. In 2012, we played Teddy Richards and he didn't really walk all week, he had a crook ankle and we thought 'how about playing on Lance Franklin in the Grand Final' and he got through OK. Those are the stories that don't get talked about.

"In the end, you've just got to make the right decision to what you think is required at the time. When we have all the facts in front us, we will make that call."

- with Martin Smith

Logan McDonald at Sydney training at the SCG on Wednesday, September 25. Picture: Phil Hillyard