Demons forward Sam Weideman is set to miss an extended period of time with a leg injury.

Melbourne confirmed in a statement on Wednesday that the 23-year old was "expected to be sidelined for the next 10-12 weeks" after scans revealed a stress fracture in his right leg.

It is a big blow for the Demons just a month out from the season, with fellow key forward and ace recruit Ben Brown set to miss the early rounds of the season after undergoing knee surgery last week.

Demons football performance boss Alan Richardson toldย Melbourne Media said the club would take a "conservative approach" with Weideman's rehab and could not set an exact return date.

โ€œItโ€™s disappointing news for Sam who has had a great pre-season to date,โ€ Richardson said.

โ€œFollowing some soreness in his hip region, the medical team decided to conduct a scan, which has shown a stress fracture in his femur.

โ€œWe didnโ€™t expect to find anything this substantial, but itโ€™s better to get onto it now and prevent it from getting any worse.

โ€œWe will take a conservative approach and an exact return to play date will be determined by how Sam responds to the on-going rehab program.โ€

Weideman is coming off a career-best campaign for the Demons in 2020, booting 19 goals from 13 games.

He has played 44 AFL games since making his debut for Melbourne in 2016.

Melbourne face the Western Bulldogs in their sole pre-season clash on March 8 at Marvel Stadium before opening their season proper against Fremantle on March 20 at the MCG.