Collingwood coach Nathan Buckley has refused to blame off-field distractions for his team's 15-point loss to Essendon on Friday night.

Their vice-captain Steele Sidebottom was hit with a four-game ban for his COVID-19 protocol breach, but Buckley said the incident hadn't put the Pies off their game.

"I'd say [it had] nought [influence on the players]. In the end there's a fair bit happening in the environment and we've been pretty good at drawing the line between what happens during the week or what happens off field and then what we do on field," he said.

"There's no excuses from our behalf in regards to that. We just weren't good enough tonight."

He also said Mason Cox needed to impose himself on games more after the key target dropped several marks and went without a kick throughout the contest.

Cox, who kicked one goal against the Giants last week, finished with two handballs and one mark in the loss to the Bombers.

"There was a game he played a couple of years ago when he hardly had a touch but he executed his role really well. He was one of a few who really struggled to have a contribution tonight," Buckley said.

"He's not on his own. Big fellas can still be effective in slippery conditions because they provide a target and they provide a beacon and even though 'Coxy' didn't get a lot of it he was pretty important for us in that last quarter as a target for us.

"But no, it wasn't a great one.