Homesick Irishman Connor McKenna could be back for Essendon as soon as round one, according to assistant coach Mark Harvey.

McKenna flew back to Ireland for "homesickness and family-related reasons" a fortnight ago, placing his immediate playing future with Essendon in doubt.

Speaking to the media on Tuesday at Tullamarine, Harvey expected the defender to return to the club "maybe early next week".

Harvey hopes he will be joined injured stars Anthony McDonald-Tipungwuti (calf), Michael Hurley (shoulder), Tom Bellchambers (knee), David Zaharakis (ankle), Orazio Fantasia (hip), Cale Hooker (hip) and captain Dyson Heppell (foot) in the club's season-opening clash against Fremantle.

Harvey spoke about how the Bombers and McKenna have kept in touch in recent weeks.

"We've been in constant contact, the club, with Conor over the period of time that he's been away, hope he's enjoying himself and relaxing," he said.

"We'd like to think that he comes back pretty soon and hopefully we can have him available for selection too. It's looking promising and our support staff have done an enormous job with this.

"He's done the majority of pre-season [training] and he's still training over there. Conor is a guy that comes up really quick ... so I would say that Conor, pending when he does come back, that he'll be available for round one."

With Essendon now less than a month from their round one clash against Fremantle on March 21, Harvey spoke positively about their injured stars returning.

"What people need to understand is once players have been around for a [long] period of time, like Zaharakis and Bellchambers and Hooker, they know how to get themselves right pretty quick," Harvey said.

"They're working as hard as they can in cross-training to strengthen the areas where they've had operations.

"In the next three weeks we get a chance to time our list and get them ready for round one and I think we'll be in a good situation come Fremantle."

The other major story to come from Tullamarine this off-season was the axing of reigning best-and-fairest Zach Merrett as vice-captain after three years. Harvey spoke about how the star is dealing with his omission.

"I would expect Zach just to play the way that he normally plays, and you wouldn't know it necessarily that that's happened and that's a credit to his character ... he's taken it on the chin," Harvey said.

"In his mind he's moved on. He's more determined than ever as a player to get this group where it needs to get to and I'm sure you'll see Zach at the forefront of a lot of the things we do."