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.”