COLLINGWOOD failed to make the most of its opportunities in front of goal and that was the difference in its first loss in eight successive weeks in the game against West Coast at the MCG on Sunday, coach Nathan Buckley says.

The Magpies raced to a 20-point lead early in the first quarter and were dominating in just about every facet of the contest, but ultimately could not convert inside 50s into scores.

Collingwood had just three individual goalkickers as it booted 9.13, with Buckley conceding a high number of his players had their "colours lowered" in the 35-point loss.

"Our ball use looked really clean and crisp early, we just weren't able to finish off well enough," Buckley said.

BUCKS ON THE LOSS Watch his full media conference

"Our ball use looked really clean and crisp early, we just weren't able to finish off well enough," Buckley said.

"When the sun was shining for us we didn't put a gap in it and we went into half-time four points down.

"Then when the clouds started appearing for us and the sun started shining for them, they were able to hit the scoreboard when we weren't. It was a tale of two halves really."

Collingwood had just 19 inside 50s after half-time to West Coast's 29, with the Eagles without star ruckman Nic Naitanui.

The Magpies were out-tackled 42-64 and allowed the Eagles 104 uncontested.

Eagles Jeremy McGovern and Shannon Hurn were particularly influential in denying Collingwood safe passage into their forward line.

"I thought there were even some signs early in the game that some of their contest was going to be worrying for us," Buckley said.

"They were still winning their fair share of contests behind the ball, which prevented us from kicking a bigger score, and when they got access to their forward line they were actually winning some contests there as well."

Buckley said his players were as fumbly and as indirect with their ball use as they had been all season.

"We had plenty of boys today who lowered their colours on their expectations and on where they've been and when that happens it's invariably the old maxim: 'When you lose more positions than you win, it's pretty hard to win the game' and that's what happened today," Buckley said.

Mason Cox, a late withdrawal because of a tight hamstring, is a chance to return for next Saturday's clash against North Melbourne at the MCG.

Brayden Sier (corked left quad) and Tom Langdon (right knee) will be assessed, but should also be available for the game with the Roos.

"We anticipate Coxy will be right to go. It was touch and go about whether we were going to play him or not and we ran it right to the line.

"He was pretty tight in the hammy – he had some neural signs and our medicos made the decision to take him off the table and proof will be in the pudding going forward whether that's the right call."

Buckley was pleased with young defender Darcy Moore's return after more than six weeks on the sidelines with a hamstring complaint.

"That was a clear positive for us. One for him to get through the game in fine fettle and to look pretty sharp, and I thought he made some really good plays," Buckley said.