LUCKLESS St Kilda forward Paddy McCartin has been ruled out of Saturday night's clash with Collingwood at Etihad Stadium as he deals with concussion. 

It's his seventh such injury since 2014 and has contributed to the 22-year-old having played just 29 career games.

"Paddy McCartin has to have further concussive tests but there is a chance that he plays next week, not this week," St Kilda head physiotherapist Andrew Wallis told 

Meanwhile, defender Jake Carlisle is no certainty to face the Magpies after he was concussed in last Saturday's loss to Fremantle. 

"He'll have some testing this week and if he passes that, he will be available for selection," Wallis said.

Former Port Adelaide defender Logan Austin would be in line to make his club debut if Carlisle isn't declared fit while Brandon White and Bailey Rice are smaller options who excelled in the VFL at the weekend. 

Sam Gilbert is no certainty to face the Pies as he deals with a reoccurence of his right ankle injury.

Small forward Darren Minchington is set to play a half for Sandringham against Richmond on Saturday if he trains well while Josh Bruce isn't far away as he deals with a lumbar stress response in his back. 

"We're hoping to get him back in two weeks," Wallis said. 

Rookie Doulton Langlands has a hamstring concern and will miss another week.