St Kilda midfielder Luke Ball will be given until Thursday to prove he's recovered from a hamstring tear that's kept him sidelined for the past five weeks.
Ball, who is desperate to return to take on Collingwood in Saturday night's cut-throat semi-final at the MCG, hasn't played since tearing his hamstring against Port Adelaide in Round 18.
But senior coach Ross Lyon has said he's not prepared to gamble on Ball's fitness and stressed the club's fortunes would never hinge on the availability of a single player.
"We will have a clearer picture after Thursday's main session ... but we won't be taking in anyone that won't be able to compete for the full minutes of the game," Lyon said at Moorabbin on Tuesday.
"It's critically important that we get an even team performance."
"He's progressing well and ticking the boxes and if he keeps going then we're going to have to make a decision at the end of Thursday."
Versatile defender Jason Blake appears set to line-up despite finishing Sunday's 58-point loss to Geelong on the bench with what appeared to be a serious arm injury.
"I thought he'd broken his wrist, to be honest, the way he was holding it," said Lyon.
"He had a bit of a dead arm but we're 98, 99-per-cent confident he'll play."
Lyon said it would be a 'bold decision' to bring back ruckman Michael Gardiner who was outstanding for the Casey Scorpions in the VFL at the weekend and who'd 'smashed himself' on the training track in a bid for promotion.
Asked whether he was bold enough to select veteran forward Fraser Gehrig, Lyon said: "I'm bold enough, but I'm not stupid."
"He wants to play ... but we feel our forward line has been functioning."
"Koschitzke, Riewoldt, Schneider and Milne, they've been getting it done so Fraser will have to wait for his opportunity."
Lyon described the Saints as a resilient group who had absorbed their lesson and moved on from the loss to the Cats.
"We weren't allowed to do what we'd been doing, fundamentally," he said.
"Morale dropped but ... that game was put in the bin as of 12 o'clock yesterday."
"We're vibrant, we're bubby and ... we want to change the perception that's probably been taken of us now about our ability to play good football."