THE SYDNEY Swans regard Sunday's clash with Carlton at Telstra Dome as a must-win clash as they attempt to regain momentum and fight off their rivals for fourth spot.

Successive losses to Collingwood and Hawthorn have seen the Magpies move to within two points of the Swans.

With testing fixtures to come against fellow finals aspirants Adelaide, the Western Bulldogs, Geelong, Collingwood and the Brisbane Lions, the Swans desperately need to kick-start their campaign on Sunday.

"I think it's a massive game," midfielder Kieren Jack told AAP.

"The past three weeks we've been really down on form.

"If we can get back to it in this game against Carlton, it's going to give us a lot of momentum going into the back end of the season.

"It can get us back into the swing of things."

A victory is also critical for Carlton's finals aspirations as they entered the round four points off eighth spot.

Swans coach Paul Roos said dual Brownlow Medallist Adam Goodes could possibly line-up on Chris Judd and was looking for a more energetic performance from his team this week.

"The guys working for each other and working hard, that has really been the focus," Roos said.

"The players themselves need to get a bit of that excitement and a bit of that enthusiasm."

While Jack said containing Carlton's superstars Judd and Brendan Fevola was obviously crucial, he was also wary of their emerging group of midfield runners.

"They (Judd and Fevola) are the two main focal points that we are looking at, but they've got a lot of good genuine players in their midfield, (Marc) Murphy and (Nick) Stevens and players like that," he said.

Jack also said the inclusion of debutant Matt O'Dwyer would add a lot of run for the Swans.

Carlton's most recent victory over the Swans was in 2000 at Princes Park.