Essendon backman Michael Hartley is set to miss a fortnight with a hamstring problem.

Hartley hurt his right hamstring in the third quarter of his team's 38-point loss to Richmond at the MCG on Saturday night, leaving Essendon bereft of a genuine like-for-like replacement.

Bombers coach John Worsfold suggested former Brisbane Lions rookie ruckman/forward Sam Michael – the 10th and final top-up player signed by the club – could be called upon to fill the key defensive post against Fremantle at Domain Stadium next Saturday night.

"Minor hamstring but he'll miss a couple of weeks," Worsfold said of Hartley's injury.

"It's not ideal for us. We don't have, at the moment, any key defenders to come in …

"Well, there's a young player, Sam Michael, in the VFL who rucked today, and we've been planning on him learning his craft as a ruckman and playing forward a bit.

"He can go back and hold up, so that's one we can look at."

Worsfold was proud of his undermanned team's resilience to hit back at the Tigers at various stages, and was particularly pleased to generate 48 inside 50s to Richmond's 53.

He challenged his players to continue their bold approach.

"They're achieving the expectations they've set (for) each other around having a crack," he said.

"They're not giving up and not getting despondent, and not dropping their bundle if they make some errors. We just back up and we'll go again.

"Seeing Anthony McDonald-Tipungwuti coming out of (defence), and it doesn't always come off perfect, but as he gets 20 or 30 games under his belt they will start to come off perfect. He has to keep doing that to learn."

Worsfold afforded special praise for prized draftee Darcy Parish, who had a career-high 26 possessions and two goals.

"He continues to show some really top-end talent," Worsfold said.

"He helped us kick our first goal and set up a couple of good forward attacks early, to the point where we took him off five or six minutes into the first quarter, we were saying, 'There's our matchwinner coming off.'

"He kicked a couple of classy goals and had another couple of opportunities I reckon. Very exciting."