MELBOURNE has shown faith in former co-captain Jack Trengove, extending his contract until the end of 2017.

The Demons believe another pre-season will have the persistent midfielder challenging for a permanent spot in the best 22.

The respected 24-year-old has played just five AFL games since the start of 2014 (including three this season), but he has put together a full season in the VFL, playing 14 games for Casey Scorpions.

He has been in good form in the VFL, playing in the midfield and has been named as an emergency for the Demons' final round against Geelong.

Melbourne football manager Josh Mahoney told AFL.com.au the club was pleased to secure Trengove as he had built a good foundation for the future in 2016.

He said Trengove had proved this season he could get through a year of senior football.

"His form at VFL level has been very strong throughout the year," Mahoney said.

He said while Trengove's pre-season for 2016 was about rehabilitation, his pre-season ahead of 2017 will have a performance focus.

"[It] will give him the opportunity to maximise his potential and lead to some potential upside moving into next year," Mahoney said.

Mahoney said the club remained confident Trengove could return to being a regular AFL player with another full pre-season.

The No.2 selection in the 2009 NAB AFL Draft has played 84 games since making his debut in 2010 and is a popular member of the club.

"Jack has had a fantastic attitude, which has helped him in his recovery, and in that time he has been able to pass on a lot of great learnings to our young players," Mahoney said.