Essendon recruit Matthew Leuenberger is expected to be fit for round one despite an Achilles injury interrupting his first pre-season with the Bombers.

The former Brisbane Lions ruckman arrived at Essendon as a free agent in October and was in good condition on the training track before suffering the leg soreness in December. 

It has restricted his training since, and he will not play in the Bombers' opening NAB Challenge game against Carlton on Sunday. 

At Essendon's main session this week Leuenberger was training on a separate oval to the main group, but the club is optimistic the injury-plagued No.4 draft pick will be ready to face Gold Coast in round one. 

"We expect he'll be right for round one. It was disappointing his Achilles got sore over the Christmas break, but the bonus was he got in a good volume of training in pre-Christmas," coach John Worsfold told AFL.com.au.

"We've lightened off in terms of how much footy training he's done but he's running really well and progressing well, and now we're just getting him ready to play.

"He'll probably play in the third NAB Challenge game, then have a week off where he'll either freshen up or we'll keep his workload up, and he'll be ready for round one. That's the aim."

Leuenberger played 108 games with the Lions between 2007-15, including 14 games last year.

The restricted free agent chose the Bombers last year as his preferred destination after also attracting interest from the Sydney Swans. 

Worsfold is also confident important playmaker David Zaharakis can recapture his best form this season, after having a disappointing 2015 campaign.

Zaharakis was dropped from the club's leadership group in December but Worsfold said the 2011 best and fairest winning midfielder had been a standout at the club.

"His leadership has been awesome," Worsfold said.

"I'm not expecting him to produce miracles, I just want him to play his best footy. We know how good that is and I know he wants to get back to playing his best footy because he's coming into his peak years.

"I'm really excited to watch him come off the ground with a smile on his face knowing he's performed really well and that the team's tracking along really well." 

Zaharakis will play alongside top-five draft pick Darcy Parish for the first time on Sunday, with Worsfold saying Parish had "put his name right up there" for an early debut in the home and away season.

Fellow top-10 pick Aaron Francis has had a less seamless transition into the AFL system, struggling with a couple of niggling injuries in his first pre-season. 

However, after impressing in last week's intraclub match, the versatile marking defender has pushed his chances of breaking into the senior team soon.  

"We got some feedback from the new senior guys on our list who said 'Francis is going to be a very, very good player' and that was just after the first quarter," he said.

"He's an imposing figure. For a first-year player to launch in front of a pack of key-position players who are going to crash into him and still take the grabs, it was imposing. 

"He's had a lot lighter load [than Parish]. He's one we don't want to play and then cause him to sit out a number of weeks."

Francis is expected to feature for the Bombers later in the NAB Challenge.