Sydney Swans co-captain Kieren Jack may be a shock inclusion for his side's semi-final clash with North Melbourne on Saturday night after getting through a solid running session on Tuesday.

As well, defender Nick Smith looks almost certain to be passed fit after recovering from a hamstring strain, but both Jack and Smith will need to pass fitness tests at the Swans closed session on Thursday.

As reported by AFL.com.au, Jack did laps of the SCG away from the main group with his left knee strapped, and looked to be going at around 80 per cent at times in the warm Sydney weather.

He strained the medial ligament in his left knee against Gold Coast in round 23 and was expected to be sidelined until at least preliminary final weekend, but the tough onballer is desperate to play the Kangaroos.

Smith tested his hamstring with short kicks over 20-30m and will play if he gets through training without a mishap.

Fellow midfielder Luke Parker is also on the comeback trail form a broken leg and joined the pair on the track on Tuesday, but the Swans have already ruled him out of this week's final.

The reigning club champion had his right lower leg covered by a compression bandage and only ran with a slight limp, meaning he could make his case for a recall if the Swans beat North to reach the last four.