Wells firms for return against Swans

North Melbourne face a huge challenge against Sydney to keep their record-breaking unbeaten start to the AFL season going, but speedster Daniel Wells looms as a welcome addition to their side.

Wells has missed the past two games for the 9-0 Roos with achilles soreness, but coach Brad Scott told reporters on Wednesday he was optimistic the veteran midfielder would train well and prove he was fit for a recall.

"He's obviously desperate to play but he was desperate to play last week too," Scott said.

"It's just one of those things - we won't take a risk with him if he's not quite right. We've said that all along, but we're optimistic that he'll train well."

Wells was restricted to just two games last season with a similar issue, Scott saying recently that the 31-year-old would not return to the side until he was "absolutely perfect".

Fellow veteran Drew Petrie jarred his neck in a marking contest in the big win over Carlton but was given the all-clear for Friday night's clash at the SCG by a specialist earlier in the week.

Ladder leaders North notched their best-ever start to a season with the 67-point win over the Blues, while the Swans are fourth on the ladder with a 7-2 win-loss record after their hard-fought win over reigning premiers Hawthorn.

Friday night's encounter marks the beginning of a demanding section of the Roos' draw, with tough games against top-eight sides Geelong, Hawthorn, Adelaide and West Coast to navigate in the following five rounds.

"There will be a lot of challenges put in front of us between now and the end of the season ... so far we've adapted well to them but we've got some big ones coming," Scott said.

"(The Swans) are playing really good footy, they're a pretty formidable opponent at the best of times, it's going to be a really good challenge but one that we're up for.

"We still haven't played our best footy but I felt last week was a step towards that. I thought it was a really complete performance."