THE WIDENING gap between North Melbourne's best and worst is becoming a concern, says Kangaroos' skipper Andrew Swallow. 

North Melbourne has defeated top-four contenders Port Adelaide, the Sydney Swans and Fremantle but lost convincingly to other finals aspirants Gold Coast, Collingwood and Geelong. 

Swallow told after the Kangaroos' 20-point loss to Geelong it was hard to find a reason why the team looked good one week and struggled to compete the next but it would be a focus of discussion during the week. 

"[We're] trying to grasp for answers at the moment and we just have to try to close that gap," Swallow said. "It seems like the gap between our best and our worst is growing a little bit which is concerning." 

Swallow said poor first quarters had been identified as an area to work on before Friday night's game so it was doubly disappointing to once again enter a second quarter behind the eight ball, as the team trailed by 21 points at quarter-time. 

"We've shown before we can match it with the good sides [but] just can't get it done early so it's bitterly disappointing," Swallow said. 

"We should take a good hard look and really try to drill down on what it is. It's just disappointing because we can't get it done."

It was just Swallow's second game back from injury, having not played since round 18, 2013. He had just 15 disposals but laid seven tackles, the equal-highest Kangaroo (alongside Levi Greenwood) in that statistic. 

However he was nowhere near happy with his game. 
"I was pretty ordinary tonight," Swallow said. 

The 26-year-old and three-time best and fairest winner conceded there was enormous scope for him to improve. 

"It's just taking a bit of time to get everything back. My touch is not there at the moment. My work rate is not quite there. I think I just need a couple more runs under the belt," Swallow said.