"If the group and the club feel that there's someone else that's better off to lead the group going forward, then I'm more than happy to step down and hand the reins over," Heppell said in December.
"...I want to be there still while the next captain comes through to help mentor, help guide and develop them as well."
Essendon are expected to make a final decision on their leadership group this month, with the likes of Merrett, McGrath and defender Jordan Ridley seen as the leading options to replace Heppell should a changing of the guard be confirmed.
Both Merrett and McGrath were the only players named to support Heppell as part of the club's leadership group for last year, with the midfield pair tipped to take over from their skipper in 2023.
Speaking to RSN, Bombers defender Jake Kelly said he believed the race is down to two.
"You've got two guys in Andy McGrath and Zach Merrett who are incredible leaders," Kelly said.
"Zach especially this pre-season has been really, really great. He's leading by example out there. The intensity he trains at and the demeanour he has around the club has been really impressive.
"One of those two, I presume, will take the mantle."
While unknown on the exact timeframe for Essendon's unveiling of their leadership group and potential captaincy change, the former Crow did reveal an announcement is expected to come "relatively quickly."
"I presume it'll be in the coming weeks," he said.
"Given the season is starting soon, I think that'll be a conversation that's had relatively quickly."
The Bombers are one of several AFL clubs anticipated to make captaincy calls for the season ahead, while Geelong and Hawthorn are yet to confirm their new captains after the retirements of Joel Selwood and Ben McEvoy respectively.
Collingwood have announced defender Darcy Moore will lead the Magpies following Scott Pendlebury's decision to step down as captain, while West Coast skipper Luke Shuey and Demons ruckman Max Gawn will continue to lead their respective sides.
Fremantle and Brisbane join the Bombers in placing a hold on an announcement for their leadership groups, with both Nat Fyfe and Dayne Zorko potentially ending their captaincy stints ahead of the new season.
Essendon will open their 2023 campaign against close rivals Hawthorn at the MCG on Sunday, March 19.