North Melbourne key defender Nathan Grima is finally putting the frustrations of another injury-interrupted pre-season behind him.

Grima told AFL.com.au this week he was on track to play in round one after returning to full training recently.

But Grima said that just a month ago he was so frustrated by spending another summer in North's rehab group that he "felt like chucking in the towel".

The 28-year-old's comments were made – at least partly – in jest, but there was no mistaking his frustration that a degenerative back condition had again kept him off the track.

When you have never completed a full pre-season in seven years as an AFL player and have played three of a possible 24 pre-season matches, you're entitled to feel that way.

"I'm so over being injured, this summer has just felt Groundhog Day all over again," Grima said.

"You see how well the boys are training and how fit they're looking and you start to panic and think, 'Geez, I'm falling so far behind'.

"It's an emotional rollercoaster."

Grima had known he would start the 2014 pre-season on a modified program after having a post-season operation to remove a bone spur on his foot.

The surgery meant he could not run for 10-12 weeks, but he flew to North's Utah training camp in November hopeful of building a good fitness base through a cross-training program.

However, a disc problem in Grima's back soon flared up, with rest the only real cure.

"I had an operation three years ago when I had a bit of disc taken out, which was a success because I've been able to play most weeks during the season," Grima said.

"But unfortunately it's a bit degenerative around the disc and from time to time it just re-bulges and you've just got to manage it the best you can.

"Once you get it it's quite debilitating. It makes it hard to run and do weights and generally the only way to let it settle is rest and do a lot of core (strength) exercises."

Fortunately, Grima is now getting back to full fitness and is hopeful of playing in North's second NAB Challenge match against Hawthorn at Aurora Stadium next Friday, or in its practice match against Geelong at Simonds Stadium on March 7.

And as frustrating as his pre-season has been, Grima is better equipped to deal with his late start to training than most players.

When you've never completed a pre-season, you know no other way.

Besides, Grima is a natural endurance runner who can regain full fitness more quickly than most players.

He has never played more than 17 games in a season, and eschews the notion that he should be rested from some games in 2014 to ensure he gets through the year in good health.

The defender also does not want to look beyond this year, despite the fact he is set to come out of contract at the end of the season.

"I'm feeling great physically and mentally," he says.

"I'm out of contract at the end of the year and you're never planning to finish up when you're 28 or 29.

"My priority is just to get my body right and hopefully the footy will take care of itself.

"At this stage I'm just so keen to get out there and have a great year."