BRAD Scott's challenge to North Melbourne defender Scott McMahon ahead of the 2014 pre-season was simple – get fit.

It came as no surprise to McMahon.

Not when the defender has long known he has to work harder than some players to maintain his fitness.

And especially not when a lack of fitness was the primary reason the long-time senior regular spent the final five rounds of the 2013 season mired in the VFL.

"My main and biggest goal was to start pre-season from day one, but the main thing for me was to get my fitness to a level where I am able to compete in the AFL," McMahon told AFL.com.au.

"Brad and I had spoken about heading to Utah a little bit earlier, so Sam Wright, Brad and I went over there a week early to get a little bit of extra training at high altitude in.

"I didn't miss a training session over there and, just in myself, definitely feel a lot fitter and stronger now.

"But I still have a way to go and we won't know until we get into the games how fit I actually am."

Last season was incredibly frustrating for McMahon, whose cool head and precise foot skills had made him a fixture in North's backline since 2009.

After missing round one with injury, he played the Roos' next 10 games before injuring his ankle at training in the lead-up to North's round 13 loss to Fremantle.

Sidelined for four weeks, he returned in round 17 against Carlton, but was substituted from the game midway through the third term, spending only 47 per cent of the match on the ground.

Demoted to the VFL the next week, the former rookie spent the rest of the season with North's affiliate Werribee, unable to find the fitness and form to warrant a senior recall.

"It doesn't matter who you are now, if you're not playing well we've got guys playing in the VFL who will come up and take your spot. If they play well, they can keep you out of the AFL team.

"Two, three years ago, we probably didn't have that.

"It was probably a kick in the pants for me, but something that every player needs."

In fairness, this pre-season has been the first time in two years that McMahon has enjoyed a good run of health.

Knee and groin injuries meant he could not start pre-season training until mid-January in both 2012 and 2013.

And after playing the opening four rounds in 2012 he was sidelined for six games by a severe virus that caused painful joint swelling and lasting side-effects that McMahon is only now fully free of.

But provided his change of luck holds, McMahon is set to enter the 2014 season as fit as Scott could have hoped for when he issued his challenge last September.

The 27-year-old knows being fitter and leaner does not guarantee him a return to North's senior team.

Not when the Roos' deep defensive ranks look set to be bolstered by outstanding father-son recruit Luke McDonald this year.

But that's just another challenge for McMahon to rise to.

Twitter: @AFL_Nick