ESSENDON ruckman Shaun McKernan is out of form and that's the simple reason why he finds himself out of the side ahead of the Bombers' clash against Melbourne at the MCG on Saturday, coach John Worsfold says.

Still searching for their preferred lineup in what shapes as a difficult season, the Bombers dropped the experienced trio of McKernan, Craig Bird and Jonathan Simpkin after last week's 61-point loss to Gold Coast.

McKernan, Bird and Simpkin are set to run around with the club's VFL side in a practice match against Richmond at Punt Road on Friday evening.

"Shaun hasn't been in great form over the last few weeks," Worsfold said on Friday.

"He certainly hasn't given us enough when he's been forward so that's another reason why we've had a change.

"It's very hard to run into form at AFL level so he gets an opportunity to have a hit-out with the VFL boys this afternoon and just take some marks, get some shots at goal and be more heavily involved in the game – that's what'll get him up and going better than anything."

But the Bombers coach denied the coaching panel was deliberately sending a message to the club's seasoned players.

"We've still got a fair way to go to see exactly the way we want to structure up our lineup so it's meant that from round one to round two, and possibly for the first few rounds, we'll be throwing some things around before we settle on how we go about things," Worsfold said.

"The message is around being patient while we're working out how exactly we want to see things and where we're going to play players and in which roles."

Brendon Goddard, Adam Cooney and Kyle Langford did not join their teammates for a light training run at Tullamarine on Friday morning, but Worsfold assured fans that was just part of their routine a day out from the game.

Mature-age defender Michael Hartley will make his AFL debut, a big reward after a luckless two years on Collingwood's rookie list.

Hartley had to overcome some serious shoulder injuries during his time at Collingwood in 2011 and 2012 and forced his way back into the AFL system on the back of being a joint winner of VFL club Coburg's best and fairest award last year.

Another player to overcome major adversity is Nick Kommer, who will play his first match since round 22, 2013 against the Demons on Saturday.

Kommer's 2014 and 2015 campaigns were ruined by knee tendinitis in his left leg, which required three separate surgeries to correct.

Worsfold said the 25-year-old's commitment could not be questioned.

"When I arrived (in October 2015) there were still serious questions about whether he would be able to get back and play AFL footy," Worsfold said.

"We were working through our list management process so we had to have those discussions about Kommsy.

"We knew he had the attitude to get back and after all the medical advice we got he deserved the opportunity … to get back to playing AFL footy."

Essendon is urging its fans to arrive at the MCG early before its match against Melbourne as the club looks to celebrate its past greats, as part of its Make a Stand initiative.