COLLINGWOOD midfielder Luke Ball believes the ongoing Australian Sports Anti-Doping Authority investigation played its part in Essendon's huge loss to the Magpies on Sunday.

Just hours after receiving ASADA's interim report into the club's 2011-12 supplements program, the Bombers lost to Collingwood by 79 points at the MCG and were bundled out of the top four.  

However, Essendon coach James Hird declared his players would continue to show the on-field resolve that had been their trademark before damaging back-to-back losses in the past fortnight.

"Obviously there'll be suggestions of that, but we are very confident our boys are in a pretty good headspace and they'll keep playing good football," Hird said.

"There's a bit of the basics of football that need to come back into our game.

"With a lot of hard work and dedication and a mindset, we can get back to where we were a few weeks ago."

Ball, who was instrumental in the Magpies' big win, said it was not his job to assess how the Bombers were coping with the ASADA investigation.

However, he said the ongoing scrutiny could have caught up with Hird's men late in Sunday's clash.   

"It's hard to tell … I'd like to think the way we played took a fair bit out of them so there's got to be an element of that," Ball told AFL.com.au.

"But you could say late in that second half that the emotional strain might take its toll as well, but you'd have to ask them that.
 
"I think the way they've gone about it all year, they've been unbelievably resilient so I don't think they'd use that as an excuse."

Essendon lost to Hawthorn by 56 points in round 18 and followed that performance with its heaviest defeat of the year on Sunday.
The club faces an uphill battle to displace fourth-placed Fremantle, but Hird said earning a September double chance was not his team's focus.

"I think every side that's playing in that top half of the competition at the moment is just worrying about next week," he said.  

"We have to get back to playing how we want to play, which we haven't had for three or four weeks.

"Our focus isn't on top four. Our focus is on the West Coast Eagles in seven days' time."

Hird praised captain Jobe Watson, who was superb with 31 possessions in his return from a broken collarbone, standing up despite constant jeers from opposition supporters.    

"He showed tonight what a good player he is to come back and have the touch he had and lead his team," Hird said.  

"The doctors assured us he was going to be fine, and it's pretty remarkable that he can get back in three weeks from that sort of injury.

"Unfortunately he didn't have enough around him."

Hird said Courtenay Dempsey's hamstring injury was not as bad as first feared and he had not been ruled out of next Sunday's clash against West Coast at Etihad Stadium.

The important defender was substituted after pulling up sore midway through the first quarter.

"It's over a big area of his leg, which is probably a good thing ... it's not just a spot on his hamstring," Hird said.  

Nathan Schmook is a reporter for AFL Media. Follow him on Twitter @AFL_Nathan