The North Melbourne key-defender yesterday announced his retirement after a setback in his recovery from back surgery earlier this year for a bulging disc.

This next operation will fuse a disc in his spine to alleviate pain.

The 29-year-old finished with 86 games since being selected with pick 14 in the 2008 rookie draft after a stint with Central Districts in the SANFL, missing 100 games due to injury in that time and never played more than 17 games in a season.

As well as his issues with his back, he also missed 2008 season with a knee injury, a stress fracture in his foot and finger and hand problems over his time at the level.

“I wish I could have got to 100 games and got my name on the locker but I played 86 more than I ever thought I would,” Grima said on North Melbourne's website on Wednesday.

'It’s embarrassing because Glenn Archer is in the room (when he announced his retirement to his teammates), a three-hundred game legend, so you don’t want to overstate your career but I’m stuffed if I know where I’d be without football.

“Everyone in here has had a big impact on my life. When you finish up, it’s really difficult.”

Grima, who made his debut in 2009, admitted that he ''never felt comfortable'' at the AFL level.

“I never thought I was good enough, but from the minute I played my first game I never, ever wanted to play another VFL game.''

An excellent exponent of the defensive spoil, he played a key role in the North's back-line in a career where he averaged 17 touches and five marks a game.

He was able to achieve one AFL dream last year though, when he was part of a winning finals unit against Essendon and Geelong, before the Roos crashed out at the preliminary final stage.

North coach Brad Scott paid tribute the 192 centimetre,  94 kilogram Tasmanian defender.

“At times we played him on guys that were too big for him but we knew we were gonna get an unbelievable contest,” he said.

“To me, he had a career of a bloke who just competed like no other, just the ultimate competitor.

“Very early on I realised that we had a guy who was just ultra-competitive.

“Narni’s value to this club spread much further than just on the field on game day.

“The life of the party, the life of the locker room, a guy you need around a football club. When you’re going through tough times, as you inevitably do … you need guys like Narni to keep the mood up and about.

“He was part of the fabric that held this football team together.”

Grima's brothers Alex and Todd also spent time on AFL lists, while his sister Hollie was part of the Opals world champion basketball team in 2006.