JEREMY Howe is set to miss the start of Melbourne's NAB Challenge campaign after scans revealed a strain in his right hamstring.

The Demons sent Howe for scans on Tuesday after he sustained the injury in the final training session of the club's pre-season camp at Maroochydore last week.

Howe was managed conservatively at training this week and only participated in light ball work at Gosch's Paddock on Wednesday morning.

Demons football manager Josh Mahoney told Howe would miss up to three weeks of pre-season training, but the club was confident he would be available for the start of the season proper.

"Jeremy had an incident on the last day of our camp to the Sunshine Coast," Mahoney said.

"Scans have revealed that he's got a strain in his hamstring.

"Given the position of the injury, within his hamstring, we'll treat it conservatively but we don't expect him to miss the start ofthe season."

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Mahoney said the club still expected Howe to be available for the latter stages of the NAB Challenge series, which begins for Melbourne against Fremantle on March 5.

However, the news is better for gun midfielder Bernie Vince, who has also had his pre-season interrupted by a niggling hamstring complaint.

Vince trained away from the main group on Wednesday morning and ran a series of timed laps. Mahoney said the onballer was getting close to joining in full training again.

Defender Jack Grimes also had minor surgery to fix a broken nose on Tuesday and trained in the rehab group on Wednesday morning.

However, he won't miss any training time with Mahoney confirming Grimes would be back in full training on Friday.