It may be time to change the academy system for the AFL's expansion clubs, Paul Roos said, ahead of Melbourne's match against Gold Coast. Both the Suns and the Dees have three wins and three losses for the season and Melbourne will travel to Queensland to take on the young club on Saturday.

Roos spoke carefully when asked about the system, which was created to pump high-quality draftees into Gold Coast and Greater Western Sydney.

The Giants thumped reigning premiers Hawthorn on the weekend, and the size of their catchment area in particular has come in for scrutiny.

Asked whether the system was fair, Roos said it was worth questioning whether it was time to make a change.

"Probably based on what I'm hearing, and I don't know enough about the draft this year, what I'm hearing is yeah it is," he said.

"The Suns and the Giants came in as fledgling teams with young kids, the AFL tried to put in place a system that allowed them to get better quicker.

"What I'm hearing is the recruiters are saying enough's enough."

After last Saturday's loss to St Kilda Roos said his team had not played the style of game for which they had been training, something they hoped to rectify this week.

Melbourne had not covered the ground well enough on the weekend and were frequently outnumbered in contests and Roos said he had spoken to the players about that.

"If the other team beats you to contests all over the ground it's very hard to win, and that's what St Kilda did," he said.

Roos said Melbourne had been able to score well at the weekend but their defence had been poor.

"It's hard to win a shoot out at Etihad because we don't play there enough, you shoot out against St Kilda good luck, Bulldogs, North, for us that was a big focus," he said.

Roos said he was not surprised 22-year-old midfielder Jack Viney had emerged as a potential Brownlow medal winner, because he worked hard and was a good role model to other young players at the club.

"He's a really good learner, a really good listener, he's got really good fundamental footy traits, good speed, good endurance and we know he's hard around the footy," he said.