Coach Brett Ratten will swing the selection axe in a bid to salvage St Kilda's AFL season after the Saints were humiliated by the Western Bulldogs.
The Saints barely offered a whimper after quarter-time in Saturday night's 111-point thumping and tellingly lost the tackle count, despite being thrashed in clearances and inside-50s.
"It's unacceptable and we've got to do something about it," Ratten said.
"We can't just keep going with this good quarter here or there.
"Players that aren't performing will have to go back to the twos.
"We've got some players that are in pretty good form in the reserves and we'll have to make some changes because we can't have that."
Ratten said the players had been put on notice post-match, citing the likes of Luke Dunstan and Mason Wood as strong VFL performers set to earn their opportunities.
"Eight days ago (against Geelong), win, lose or draw you hold your head up high but after that, you don't know where to look, and we can't have that.
"It's a tough game, AFL, but you just can't just drop off the face of the earth and have a performance like that."
The loss was St Kilda's fourth heavy defeat this year after losing to Essendon by 75 points, Richmond by 86 and Port Adelaide by 54.
Ratten said the Saints were attempting to ascertain why they were copping regular heavy defeats but said their issues were "all above the shoulders."
St Kilda made a semi-final last year but currently sit 4-6 and Ratten admitted it would take a lot to turn things around.
"It's going to take a bit of work, isn't it?" he said.
"If we keep going up and playing reasonable footy and then just falling the next week or a week later, it's going to be pretty tough for us.
"We need to get some consistency and I think we as a team need to deal with some of the facts in front of us right now and we can't have the fluctuations in games like we are.
"Whether we get to the point that we want to by the end of the year, that'd be good.
"But I think it's all about what we do next week because we need to make some changes and we need to address the things that are popping up all the time."