Jack Watts has pressed his claims for inclusion in Melbourne's round-one team, but the Demons are likely to have lost versatile defender Colin Garland for the season.
Watts needed the extra match fitness after he wasn't selected for the club's first two pre-season games for failing to meet selection criteria.
The 25-year-old had 17 possessions, five marks and kicked two goals in Casey's VFL practice match win over Port Melbourne at Casey Fields on Sunday.
But a club spokesman confirmed Garland would be sent for scans, which are expected to confirm a ruptured anterior cruciate ligament.
The 28-year-old was injured in a marking contest in the last quarter of the match and taken from the field on a stretcher.
He will miss the entire 2017 season if he undergoes a knee reconstruction.
The Demons look set to be short-handed in defence when they face St Kilda at Etihad Stadium on Saturday afternoon, with Sam Frost and recruit Michael Hibberd ruled out through injury.
Dom Tyson (knee), Jeff Garlett (hamstring) and Joel Smith (toe) were among the AFL-listed players to impress as they make their way back from injury.
Tyson amassed 18 possessions in the heat-shortened hit-out, Garlett impressed with his forward pressure and kicked two goals and Smith had 16 touches and kicked a goal.
Practice matches at the weekend provided several players with opportunities to prove their fitness for round one.
North Melbourne key forward Ben Brown pressed his claims for inclusion in the Kangaroos' round-one side to face West Coast with an eye-catching hit-out for Werribee.
The 24-year-old missed North's pre-season series games as he recovered from the knee surgery.
He was one of 15 North Melbourne players to take part in a VFL practice match against Sandringham and impressed with three goals.
"It's down to the match committee to decide now ... I think I've put my name forward as well as I could have done," Brown said.
"I haven't got a perfect knee but everyone's got different things going on with their bodies at various stages of their careers.
"But it's feeling as good as it's felt for my whole career really."
Majak Daw booted two goals before suffering an eye injury, with Scott Thompson, Lachie Hansen, Jed Anderson and Sam Wright among the other key Roos to get extra match practice.
Essendon tall Cale Hooker is also in the frame for a round-one clash with Hawthorn after kicking two goals in a VFL practice match against Geelong on Friday night.
Hooker hasn't played since round 23, 2015, after serving a doping suspension last season, and has been slowed by a hamstring injury.
Cats AFL midfielder Cameron Guthrie also took part in the game in a bid to prove he is over the ankle injury he suffered in the first game of the pre-season series.