MELBOURNE has suffered a huge blow on the eve of the season, with defender Colin Garland in danger of missing the year with a serious knee injury.

The 28-year-old suffered a suspected torn anterior cruciate ligament while playing for Casey Demons in a VFL practice game against Port Melbourne at Casey Fields on Sunday.

Garland was involved in a marking contest in the last quarter when he landed awkwardly and had to be stretchered from the ground.

He will have scans on Monday, but the club believes he has ruptured his ACL.

Garland has played 141 games for the Demons, but made only six appearances last year with the emergence of Oscar McDonald.

He was in line for a recall to the senior side for Saturday's round one clash with St Kilda at Etihad Stadium.

The Demons are already stretched defensively with Michael Hibberd (Achilles) and Sam Frost (toe) to miss the season opener, and full-back Lynden Dunn traded to Collingwood at the end of last season.

Rookie Joel Smith will come into contention after a solid game for Casey, but will need to be promoted to the senior list.

Midfielder Dom Tyson boosted his match fitness ahead of the match with the Saints in his second game back from a knee injury.

Tyson had 18 possessions as Casey defeated Port Melbourne by 44 points – 17.6 (108) to 10.4 (64) – in hot conditions.

Forward Jack Watts pressed his claims with another solid hit-out, finishing with 17 disposals, five marks and two goals.

Watts was overlooked for the Demons' first two JLT Community Series games after a poor pre-season before he returned for last week's match with West Coast.

Half forward Dean Kent had 12 touches in his first game of the year after being sidelined with a back injury, while small forward Jeff Garlett had 10 possessions and booted two goals.

Garlett stood out with his pressure in the forward line and constantly kept the Port Melbourne defenders on their toes.

Smith (16 possessions, one goal) did his chances of a senior call-up no harm with his offensive rebounding out of the backline.

The 191cm defender is the son of former Demons high-flyer Shaun Smith and was recruited as a category B rookie at the end of 2015.

He spent last year in the VFL developing his game after coming across from basketball.

Draftee Mitch Hannan (12 possessions, two goals) impressed with his ability to win his own ball in the forward line and create play when he had the chance.

The Demons bolted out of the gates in the 35-degree heat, booting seven unanswered goals in the opening quarter while keeping their opponents scoreless.

Port Melbourne – which isn't aligned with an AFL club – responded in the second term with five goals to trail by 23 points at the main break as the Demons' intensity wavered.

The gap closed to 14 points at three-quarter time before the Demons kicked five goals to none in the last term to secure the win.