St Kilda were forced into a late team change for its all-important elimination final bout with GWS at the MCG on Saturday afternoon, with key forward Tim Membrey removed from Ross Lyon's side to face the Giants due to a personal health matter.

Membrey was replaced in St Kilda's starting side by Anthony Caminiti just hours prior to the 3:20pm (AEST) bounce, with the Saints needing permission from the league to bring in a player who was not named as an emergency.

St Kilda provided a statement on Saturday morning that noted "Tim's health and wellbeing is our primary concern".

Speaking to 3AW ahead of his side's opening final, Lyon said Membrey was "safe" and "fully supported".

"I had a call at 8:16am this morning from our doctor. Can't say a lot except that overnight (Membrey) was unwell," Lyon revealed. "We put a triage of support in place as a club.

"I met with the players as I just had to take control of it, you don't want 40 conversations. We sent a text message out, and conveyed it to the AFL and then the Giants and they respectfully allowed emergency consideration for Caminiti (to be named).

"When the players came in today I addressed it just to assure them Tim is safe, fully supported and that they can concentrate on the game."

Max King and Seb Ross were named as St Kilda's initial inclusions at team selection, with Jack Hayes, Liam Stocker, and Ryan Byrnes all out of the Saints' Round 24 lineup.

The Giants included Sam Taylor and Finn Callaghan at the expense of Nick Haynes, Ryan Angwin, and Toby McMullin.

St Kilda and GWS are scheduled to face off at the MCG on Saturday for a spot in a semi-final next weekend against one of Brisbane or Port Adelaide.