NORTH Melbourne defender Scott McMahon concedes his fitness and form was not up to scratch in a "disappointing" 2013 season.

A fixture in the Roos' backline since 2009, McMahon made a slow start to 2013 after missing most of the pre-season and then missed five weeks mid-season with an ankle injury.

He returned for North's round 17 clash with Carlton but struggled and then spent the rest of the season in the VFL.

Speaking from North's Utah training camp, McMahon told injury had been a significant factor in his poor 2013 season.

"I was just frustrated that the season started as it did with not being able to do pre-season (training) at all and then also doing the ankle at training, which is never a good thing," McMahon said.

"I don't think my confidence was down, it was just a [bad] year."

Having overcome his injury problems, McMahon's primary goal this pre-season is to get his fitness up to AFL standards.

"I think Brad (Scott's) biggest thing is just to get the fitness back to where it needs to be and make sure I stay on top of that and also just make sure my body holds up where I'm able to do the majority, if not all, of the training," McMahon said.

"That's the biggest thing for me. If I don't keep up with the core (strength training) and all that, my body's just going to break down again."

McMahon has already made a good start to his fitness campaign.

Along with teammate Sam Wright, he arrived at North's Utah camp a week earlier than the rest of the team, determined to get in extra training at high altitude.

According to North's website on Friday, McMahon's running has already improved after two weeks in the US.

McMahon admitted he still had "a fair way to go" before reaching peak fitness, but said he was confident he could so and force his way back into North's best 22.

"If I didn't think I was going back into the team I probably wouldn't be here. I'm sure that's the same for everyone on the list," McMahon said.

"You are just making up numbers if you don't think you are going to make the team and then you are not taking it seriously enough

"I do think I can get back in the team and make a really good impact."

Twitter: @AFL_Nick.