A SHOULDER injury has forced dangerous Collingwood forward Alex Fasolo out of Saturday night's big clash against Adelaide.

Fasolo returned against Greater Western Sydney last Saturday but jarred his shoulder towards the end of the game and the Magpies decided to take a cautious approach this week.

Collingwood coach Nathan Buckley said Fasolo wanted to prove his fitness at training on Thursday but the decision was made to rule him out.

"He jarred it last week. It was touch and go but we don't think he will come up," Buckley said.

Midfielder Levi Greenwood is in line to replace the sharpshooter after being managed last week, but American Mason Cox has not been able to force his way back into the seniors.

Buckley said it was tough to change a winning line-up, with selection pressure growing as Collingwood's injury list was reduced. 

The coach said Cox had been impressive since making his debut on Anzac Day but appeared to need a break ahead of last week's clash, when he was rested.

Buckley said key forward Travis Cloke was likely to pay the $1500 fine applied for wearing a glove last week against the Giants that had not received AFL approval.

Buckley wore a glove to the media conference, making light of the controversy over key forward Travis Cloke being fined $1500 for playing with a non-approved glove last week.

However, he said players had been reminded at Thursday's morning meeting that it was their responsibility to ensure they wore the correct gear.

"We won't be making that mistake again," Buckley said.

Cloke, who kicked four goals against the Giants, did not wear a glove at training on Thursday, but Buckley said it was not something Cloke wore purely to help him mark.

"It was done more for a medical reason of looking after his finger. He's worn a glove for the most part throughout his career but in the end, if it is not ratified by the AFL you can't be doing it," Buckley said.

After three wins in succession, the Magpies' confidence is building, but Buckley is under no illusions as to the test the Crows will provide on Saturday night. 

"Outside of the two sides who play tonight [Sydney and Hawthorn], Adelaide are the best side in the competition," he said. 

"They are hitting the scoreboard hard, they have improved their defence as the year has gone on, and one of their favourite sons [Scott Thompson] is playing 300 games at their home ground. 

"This is as big an ask as the competition is supplying at the moment, and we are really looking forward to going over there and testing ourselves in the fiercest of cauldrons."