Demons ruckman Braydon Preuss has suffered a knee injury at training and is facing a delayed start to the 2020 campaign.
He has been ruled out for up to 10 weeks.
Preuss, 24, suffered a medial meniscus tear at training on Monday after going down towards the end of the clubs training drill.
Melbourne's general manager of football operations Josh Mahoney told Melbourne Media the setback will have a damaging effect on the Demons' campaign after a strong pre-season from Preuss.
โUnfortunately during training yesterday, Braydon landed awkwardly on his right knee, with scans revealing that he has sustained a medial meniscus tear,โ Mahoney said.
โBraydon underwent surgery to his right knee on Tuesday afternoon. We felt this was the best course of action to prevent any further issues moving forward.
โAt this stage we expect Braydon to be unavailable for eight to 10 weeks.โ