When the realisation sunk in that he was going to have to undergo back surgery for the second time in little more than four years, Nathan Grima initially wanted to quit AFL football.

It was an understandable reaction.

Few players have endured as many injuries as Grima has since he joined North Melbourne in the rookie draft at the end of 2007.

Despite being an almost automatic senior selection since 2010, the key defender has played just 86 games in his seven seasons at Arden Street. A litany of back and knee injuries are chiefly to blame, but a navicular stress injury sidelined him for 11 games in the middle of last year.

So when Grima's back seized as he ran in to pick up a ball during a routine kicking drill a few weeks ago, the 29-year-old was concerned.

His concern grew when some treatments North's medical staff had used successfully in the past to "settle" his back did not work, with his discomfort initially so bad he could not even drive to training.

And when specialists confirmed his worst fears that he needed surgery to remove a piece of bulging disc Grima started to question whether it was worth putting his body through the rigours of AFL football anymore.

The Tasmanian had already undergone a similar operation on the same disc on New Year's Eve 2010.

Last Wednesday's operation was the ninth of Grima's career and he told AFL.com.au he initially wondered whether he had used up all his football lives.

"I guess when you start to compound all of your injuries into one you can find yourself in a bit of a hole and you start to doubt yourself and your passion for the game really comes under question," Grima said.

"I've had a knee construction (in early 2008) which was obviously not ideal, but when you've had your back cut open for the second time – and you don't know the amount of treatment and things I've done to try and get that right – obviously you think, 'Why do I bother really? Am I doing all this really just to play a game of footy?'

"And you probably look a bit beyond just playing football and think about just enjoying your life. In the initial short-term the last thing on my mind was playing football, that's for sure.

"If you asked me a week ago what I wanted to do I probably wanted to quit, but it's just lucky I've got good people around me.

"My fiancée, Jacinta, was the one who tried to keep me positive and I've got a good family. They just sort of keep you focused and you come out of that little bit of a slump.

"And being a person who loves footy and loves a challenge now that I've actually got through the first week of (recovery) I can't think of anything that I want to do more than get back and try to be in a team that could have some success later in the year with a bit of luck."

Grima said last Wednesday's operation had gone according to plan, with his surgeon removing a "substantial piece" of bulging disc.

The defender said his disc problems had disrupted him in every pre-season since 2011 and had got progressively worse until this month's flare-up.

Grima said if he hadn't had surgery his AFL career would have been over.

"I believe if I left [the bulging disc] in there I never would have played AFL footy again because I couldn't have got fit enough and I guess although this is not ideal it's given me the only chance I've got to get back and play," he said.

"I'm back to square one but hopefully I can go forward with no discomfort and get strong enough and fit enough and get back and play some more football."

Grima is expected to be out for 12-14 weeks, which would sideline him until round seven at the earliest. Even then, he would presumably need to play at least one or two games in the VFL before earning a senior recall.

North coach Brad Scott said last week he was confident Grima could get back and play an important role in the last two-thirds of the season.

The defender, who comes out of contract at the end of this season, shares his coach's positivity.

He knows "quite a few" other AFL players who have had two operations on bulging discs and returned to the field successfully.

And he can draw on his ability to return from last year's navicular injury and play in six straight wins, including the finals victories over Essendon and Geelong, before North's season ended with a 71-point preliminary final loss to the Swans.

"It gives me good confidence knowing I ended up playing in a finals series last year off the back of having 12 weeks off during the season when I couldn't run at all with my navicular and I couldn't train at all really through the finals," Grima said.

"Although I wasn't at my absolute best I thought I could still compete relatively well and the operation I've had now is going to allow me to be much fitter than I was last year.

"My foot has healed now so I've been able to run and train. Obviously I'm going to have to get back and get fit and get in the team but I potentially could be in a better position at the end of the season this year than I was last year.

"But my aim in the short term is just to get my back right and get healthy and then I'll have a fair dinkum crack at getting back, whenever that might be later in the year."