Collingwood coach Mick Malthouse has put several of his underperforming Magpies on notice - lift against St Kilda at the Dome on Friday night, or face the consequences.

Malthouse said a number of his players whom he declined to name had failed to take the step forward expected of them this season and were now on 'the last line'.

"There's three or four blokes who have been very handy players for us, but they really haven’t improved this year for one reason or another," Malthouse said at the Lexus Centre on Thursday.

"That means that (other) players have gone past those blokes or they just haven't been able to pick up from where they were last year."

"(Friday night) is going to tell us a little bit about a few players … and we may be on the last line with a few blokes who are just going."

"That's a good test for them, a real good test."

In the wake of the Pies' heavy Round 7 loss to Hawthorn, Malthouse singled out several players for criticism at his post-match media conference including defenders Tyson Goldsack and Harry O'Brien whom he said were 'off their game', and Travis Cloke who 'didn't get near the football'.

Asked on Thursday to comment on Dale Thomas' form, Malthouse said, "Dale hasn't played as well as he would like."

"He knows he's got to change his fortunes."

Malthouse was philosophical about the prospect of losing No.1 ruckman Josh Fraser for Friday night's match because of the posterior cruciate ligament injury sustained while representing Victoria in last Saturday night's Hall of Fame Tribute match.

"No-one likes to see a player get injured regardless of which club he is, and particularly if he's your own player, it's the last thing you need," he said.

"But players who aren’t out there don't win games of footy so you get over it very quickly."

"It might be annoying to supporters … perhaps not having the best players out there … but, at the end of the day, that's just the way the game is played."

Malthouse hasn't entirely conceded, however, that Fraser, who was restricted to training indoors on Thursday, will not come up.

"He's struggling a little bit, so the likelihood is we'll debate whether we name him to give him a chance tomorrow morning but if we name him it doesn’t mean he's in the side," he said.

Anthony Rocca, sidelined since Round 5 with a chronic ankle problem, has been 'looking good' according to Malthouse and appears likely to return to the line-up.

"I certainly hope that he's a bit more advanced than last week," he said.

"He works very hard, Anthony, contrary to what some people think - he works extremely hard to get right, so we're highly optimistic that he’ll play."