MELBOURNE is facing the prospect of being without star midfielder Bernie Vince for its round one opener against Gold Coast at the MCG, while doubt has also been cast over Jeremy Howe's availability.

Vince has suffered a setback in his bid to return from a niggling hamstring injury, with the Demons not expecting him to train for the next month.

The gun onballer has had an interrupted pre-season after undergoing shoulder surgery at the end of last year, meaning he may not have the continuity in his training to be ready for the start of the season.

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"Unfortunately Bernie re-injured his hamstring quite late in his recovery from the original injury and he’s started back in the rehab process," Demons football manager Josh Mahoney told the club's website.

"It'll be two to three weeks of training before he gets ready to play again.

"He's missed quite a bit of pre-season, originally with a shoulder injury, so we’ll have to make a decision on how much training he has to do before he's cleared to play again."

Howe injured his hamstring during the club's pre-season camp to Maroochydore in January and the Demons decided to take a cautious approach in his recovery.

However, despite the time that he has missed, the Demons are hopeful Howe may feature in some form of NAB Challenge action.

"Given the position of the injury in his hamstring, we were always going to treat this conservatively," Mahoney said.

"Jeremy's progressing each week but we still expect him to be two or three weeks away from starting to get back into training and then to start playing games."

That Chris Dawes is suspended for round one, due to an incident for a bump on North Melbourne skipper Andrew Swallow in round 23 last season, places extra pressure on a forward line containing the likes of Jesse Hogan and Jeff Garlett.

Prized draftee Christian Petracca, who had season-ending knee surgery on Tuesday, was also firming for a round one debut before rupturing his anterior cruciate ligament at training earlier this month.

Petracca had surgery on Tuesday and Mahoney said the procedure went off without a hitch.

The club is already looking at ways for him to stay involved at training and in different capacities to complement his rehabilitation.

"He'll just start the rehab process for the next period of time and, given that he’s out for a long term, we'll work closely with Christian on building a plan for what the next nine to 12 months looks like for him," Mahoney said.

"This will include doing some different jobs around the club, assisting with potentially some scouting of opposition clubs and recruiting, and also having some time away from the club to make sure that he stays mentally fresh during this period."

Jack Trengove, who remains sidelined indefinitely after foot surgery, has also made headway in his recovery.

"Jack has progressed out of the moon boot now and he’s walking around in runners which is a big progression from where he has been,” Mahoney said.

"So he’s starting to increase the load on his foot and hopefully it continues to repair as it has so far."

The Demons are likely to place Trengove and/or Petracca on the long-term injury list, meaning rookie midfielder Aaron vandenBerg could be elevated to the senior list.

VandenBerg did not play in the club's intra-club hit-out last Thursday, but has impressed the Demons with his sheer size (188cm, 90kg) and his ability to locate the ball in traffic this pre-season.

The 23-year-old had an astonishing 64 disposals while playing for Ainslie in the NEAFL last season, making him a potential target for AFL Fantasy coaches as well.

The Demons face off against the Suns in the opening round of the season on April 4.

Aaron vandenBerg is a $122,000 midfielder in NAB AFL Fantasy this year. Create and fill your AFL Fantasy Classic league by March 2 to win a free AFL Live pass.