Defender Scott Thompson believes the absence of backman Nathan Grima will provide a good opportunity for other players to step up this season.

Grima, who had surgery on Wednesday to repair a disc in his back, has been sidelined from the Roos’ squad for at least three months.

Thompson said Joel Tippett, Robbie Tarrant and recruit Daniel Nielson have the ability to fill the void and offer support in North’s defensive half.

“It’s a big loss for the first half of the year without ‘Narni’ (Grima) so hopefully he can get back as quickly as possible, but it opens the spot up for someone else,” Thompson told NMFC.com.au.

“'Tippo' (Tippett) and 'Taz' (Tarrant) have been training really well and Nielson has also been going well, so all three talls are really looking good.”

The 193cm key defender said the trio each bring a different dimension to the Roos’ backline.

“Taz is really good one-on-one, his ability to run off his opponent is probably his strength,” Thompson said.

“Tippo’s a big-bodied defender ... and he’s got great closing speed so he’s really good at shutting down an opponent.

“Daniel is just competitive, he goes hard and can close people down.”

Thompson underwent post-season knee surgery during the Christmas break and continues to increase his workload after a short spell away from the main group.

Despite playing all but one game last season, the 28-year-old said he hopes to replicate his form from two years ago as he prepares to enter his eighth season at Arden Street.

“I think my 2013 year was better personally – I had a few more goals kicked on me last year – but in saying that (I played) a bit of a different role as well and we were better as a team (in 2014),” he said.

In addition to matching up against the power forwards of the competition, Thompson spent time playing on small and medium forwards, particularly towards the pointy end of last season.

He lined up against GWS’s Josh Kelly in round 20, Western Bulldog Stewart Crameri the following week, Adelaide’s Eddie Betts in round 22 and Essendon’s Paul Chapman in the elimination final.

Thompson said he may fulfil similar responsibilities this year – as a key defender as well as a third tall option – and make the most of his capacity to intercept opposition attacks.

Now in his third successive year as part of North’s leadership group, the number 16 admits he isn’t the most vocal on the park but instead lets his actions do the talking.

“I’d like to see myself as really setting the example in the gym, on the training track, giving it my all and leading by example on the footy field,” he said.

Rather than setting too many personal goals, Thompson said he and his fellow defenders will again set group targets, looking at ways to nullify their opponents’ influence.

“We have team goals each week – maybe marks inside 50, how many scoring shots they have inside 50, things like that – and I think that’s a better way as a team rather than an individual because it’s not an individual game,” he said.

“I more like to set team goals for the defence and if I can help us achieve that.”

But while Thompson is thriving with a team-first mentality, reaching the 150-game milestone will no doubt be at the forefront of his mind.

“When I got drafted, I said I’d be happy to play one game but then it came to ... if I could play 100 games, that’d be unbelievable,” he said, citing his journey through the AFL ranks after being drafted as a mature-aged recruit.

“Once you tick that milestone off you just move on to the next one so hopefully I can get the 150 this year.”