FORMER Melbourne captain Jack Grimes will get the chance to re-energise his football career as a wingman, starting in the NAB Challenge.

Grimes, who will be a free agent at the end of the season, struggled for form and confidence last year after missing out on senior selection in round one.

The 26-year-old regained his spot in defence, but played just 12 games and enters a career-defining season in 2016.

Melbourne coach Paul Roos told AFL.com.au that Grimes had embraced his new role, and the coaches were excited about what he had shown on the training track.

Roos added Grimes had the flexibility and endurance to play in the high half-forward role.

"He is a good athlete. He gets up and back the field really well, [and with] 90 interchange he is really [suited to] where the game is going," Roos said.

"He has really embraced that role and I think it is a role he can play really well."

Melbourne has high hopes Christian Salem can play the sweeping half-back role after his impressive 2015.

Roos said Salem was sorely missed when the 20-year-old suffered a hamstring strain last year and missed nine games.

"Often when you don't have them you realise the impact," Roos said.

"We missed him last year. For a second-year player, that is a big feather in his cap."

Roos said Salem was still learning how to make more of an impact, and had much more improvement left in him.

The coach also said Christian Petracca was unlikely to play in the NAB Challenge after breaking his toe playing basketball before Christmas.

Petracca is coming back from a knee reconstruction and is yet to play a game with Melbourne, with Roos saying his latest setback was disappointing.