Geelong have suffered a sudden scare on the eve of their preliminary final clash against Brisbane at the MCG on Saturday, with assistant coach Steven King being rushed to hospital after an incident at training on Friday morning.

King collapsed at the start of the session, suffering an apparent medical episode before being taken to Epworth hospital in Waurn Ponds, as players were escorted from the field.

The incident follows King's returning trip from Western Australia, where he met with the West Coast Eagles coaching panel as one of the contenders for the senior coaching gig.

"Geelong Cats can confirm assistant coach Steven King had a medical episode at the team's Captain's Run session this morning," a club statement read.

"Steven has been taken to hospital for further assessment and was conscious as he departed the Stadium.

"The Club's priority is Steven's health and we ask the media to please respect Steven's and his family privacy.

"The Club will provide further updates as they come to hand."

King reportedly collapsed mid-conversation with star forward Jeremy Cameron, who appeared shaken up by the incident in the aftermath.

The club expect that he will not be at the MCG for Saturday's prelim, but further updates will present throughout the waiting period until pre-game.

46-year-old Steven King played 240 games for Geelong and St Kilda as a ruckman, featuring in the Cats' historic 2007 triumph before featuring on the losing side in 2009 for the Saints against his old mob.

He was an All-Australian and former captain for Geelong, and has added to his resume through the coaching ranks, with eyes potentially on the vacant job out west.

Adding another sour note to the worrying situation, according to Mitch Cleary, star Cat Max Holmes trained away from the main group at the Friday session, isolating himself as he battles an illness.

Holmes will play on Saturday, though his capacity to perform for the cutthroat final will be on watch heading into the match.

MELBOURNE, AUSTRALIA - SEPTEMBER 16: Max Holmes of the Cats is seen injured during the 2022 AFL First Preliminary Final match between the Geelong Cats and the Brisbane Lions at the Melbourne Cricket Ground on September 16, 2022 in Melbourne, Australia. (Photo by Dylan Burns/AFL Photos via Getty Images)