In rounds four and five, the Bombers managed just nine goals each game in listless losses to Fremantle and St Kilda.

With his forward line struggling, Dons coach Mark Thompson put Jake Carlisle on notice for not working hard enough.

Buckley said he paid little attention to those comments, but was concerned about the prospect of Essendon rediscovering its potency on Friday at a sold-out MCG.

"We know they're an offensive juggernaut when they get going," Buckley said.

"We've seen some of their ball movement, their speed - it has worried a couple of the best defensive sides in he comp early in the year.

"So we're planning for that.

"There's not one possible reason for us to underestimate what Essendon are going to bring on Friday."

Key defender Nathan Brown came back earlier than expected from a shoulder injury last weekend in the VFL to be a chance of returning for the Magpies.

But young guns Lachie Keeffe and Jack Frost have been strong performers in Collingwood's defence, especially in a last-start win over North Melbourne, and Buckley has hinted at being hesitant to change a winning side too much.

"That's something you weigh up. If you're in our side, you've earned the right to be there," Buckley said.

"If you continue to perform, you earn the right to stay there."

Buckley said the significance of the most-eagerly anticipated match of the regular season would not be lost on any of his players.

"We acknowledge the opportunity it presents the club and AFL on a very significant day," he said.