MELBOURNE'S inability to match the Sydney Swans' hardness in the wet over four quarters highlighted the difference between the young Demons and the competition's elite, coach Paul Roos says.

The Demons' effort kept them in the game for the first three quarters and they trailed by 25 points at the last change.

However, the Swans pulled away in the final term, booting five goals in 13 minutes on the way to the 55-point victory.

Roos said the difference between this week and Monday's fabulous Queen's Birthday victory over Collingwood was the Swans' ability to maintain their intensity for the full four quarters.

"Last week we were the team that kept on playing and Collingwood dropped off in patches," Roos said.

"Today was the reverse. Today, we were the team that dropped off because Sydney, Hawthorn, the good teams don't really drop off.

"We felt we played really hard and tough and physical, but Sydney just didn't drop off at all throughout the course of the day."

The visitors were on the receiving end of an AFL record 155 tackles from the Swans, with Luke Parker (17 tackles) and Isaac Heeney (13) leading the way.

And while Melbourne also exerted pressure on the Swans, laying 87 tackles, it was that relentless harassment from the home side that eventually took its toll on Roos' young group.

"If they don't drop off our guys don't get much of a respite and then we drop off and they keep going and that's what happened in the last quarter," Roos said.

On a positive note, 20-year-old Christian Petracca showed some more good signs with another two goals in just his eighth senior game.

Roos said Petracca, who was the NAB AFL Rising Star nominee in round nine, and other youngsters at the club had the ability to reach the level required to compete with the top teams for a full match.

"When our guys get to the ball they generally are compete pretty well," Roos said.

"We've just got to do it for longer. We believe we've got the talent there, we can keep educating them to get to the level that the Swans have got to."

Melbourne has a week off now before hosting Adelaide at the MCG on July 3.