COLLINGWOOD coach Craig McRae is challenging his players to prove their season-opening win against St Kilda wasn't a flash in the pan.

The Magpies will be without Mason Cox for Saturday afternoon's MCG clash against Adelaide, with the American ruled out because of an ankle injury.

Magpies coach Craig McRae confirmed the news on Thursday and said fellow talls Darcy Cameron or Nathan Kreuger were in the running to replace the big American.

"Unfortunately Mason is not going to play. He's pulled up a little bit sore from the work hid do [in round one], so he's unavailable in the short term," McRae said.

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"And then it's a question of who we bring in, whether it's Kreuger or Cameron or another type ... we will make that decision in match committee this afternoon."

Kreuger - who is in his first year at Collingwood after arriving from Geelong in last year's Continental Tyres AFL Trade Period - is available after copping a heavy knock during the Pies' AAMI Community Series clash with Greater Western Sydney.

The Magpies handed over pick 41 for Kreuger and also received the Cats' pick 55. He made the move in a bid for more opportunities after managing just two AFL games at Geelong.

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McRae is urging his players to follow-up their impressive 17-point win against the Saints with another solid performance against the Crows.

"It's a hard competition and the bottom line is we have got to be able to embrace every contest that comes, wherever we play and whoever we play," McRae said.

"Now, we had a good (opening) performance but you have got to back that up. We have got to repeat those behaviours. At the moment it's not a pattern of behaviour. At the moment it's just a performance that we were pretty happy with."

Tall forward Cox hurt an ankle in the win over the Saints, notable for the stunning debut of Nick Daicos who collected 27 disposals.

"He is so professional," McRae said of the 19-year-old.

"He wants to get better, he's following up with coaches all the time ... watching tapes. He is going to get the best out of himself.

"We are seeing what he is capable of now but it's exciting to think what he could be capable of in the future."

McRae also lauded the feats of Daicos' 23-year-old brother Josh, in his fourth season at the club.

Both are sons of Collingwood legend Peter Daicos.

"(Josh) is sort of sitting there in the background a little bit," McRae said.

"I couldn't be more happy with Josh, his ability to play a role, he has had a terrific pre-season.

"He has been a little bit lost in the Daicos discussion but we are really happy with what he's bringing to the table."

- with AAP