Knee injury keeps Wagner out for a month

Melbourne defender Josh Wagner will miss up to four weeks of AFL with a knee injury.

The Demons' first pick in last year's rookie draft was not named for the club's away match against Adelaide on Sunday.

Demons coach Paul Roos is also unsure if former co-captain Jack Grimes, who has shifted to a wing role, will play his first game of the season from the interchange after being named as emergency for the 10th time in 2016.