St Kilda has scope for 'one or two' selection changes for Friday night's preliminary final against the Western Bulldogs and veteran defender Max Hudghton remains in the mix for a call-up, according to senior coach Ross Lyon.

But realistically, Hudghton's prospects appear slim given the lack of an obvious match-up.

Speaking ahead of Wednesday's training session in bright sunshine at the MCG, Lyon hinted he would wait to see what the Bulldogs come up with before determining his own final 22.

"There's definitely one up in the air, maybe two," said Lyon. "It depends on how many runners they've got, sort of game breakers."

"What I've learned is don't take it for granted - just get through the last session and tick it all off and wait for tomorrow at recovery to see if everyone's alright and there's no-one come down with a bug or anything and then finalise."

"I tend to just jump the hurdles when I have to and just stay focused on planning a good session."

Lyon said that 33-year-old Hudghton, the club's longest-serving player and sole survivor of the Saints' last grand final line-up in 1997, has a key role to play as member of the training squad.

"Max is right in the mix (for selection)," said Lyon.

"We've got about 30, 31 that we're really keeping on going really strongly that at any given time we would be happy for them to run down and represent St Kilda."

"It's a really difficult time, but that's the way it is."

Lyon said he'd taken on board the increasingly vocal campaign led by commentators and high-profile supporters including Test cricket great Shane Warne and former St Kilda coaches Grant Thomas and Stan Alves agitating for Hudghton's inclusion.

No amount of pushing, however, will alter the fact that the buck stops with Lyon.

"I'm happy to make decisions - that's my job," said Lyon. "We get judged on the calls we make."

"It is difficult but the team comes first and unfortunately I can only pick 22 players."

"It's a tough time, but that's a reality of AFL footy and, at the end of the day, you pick yourself fundamentally with your form and fitness."

Meanwhile skipper Nick Riewoldt and club vice-captain Lenny Hayes, who trained on Wednesday with heavy strapping on his left elbow, have declared themselves in perfect shape for the match.

"I just copped a knock a few weeks ago but it's been fine," said Hayes.

"I've played the last couple of rounds and got through really well so it's no problem at all."

Riewoldt, who's been carrying a knee injury for much of the season that's understood to be posterior cruciate ligament-related, said he welcomed the week's break heading into Friday's match.

"It's not holding me back at all," said Riewoldt of the injury. "It's led me to a bit more modified training, but come game day I'm 100 percent and it's fine."

"No doubt a little bit extra rest was beneficial."