North Melbourne has earmarked more significant defensive responsibilities for Sam Durdin and Ben McKay in season 2020, as the club looks to its developing core of young key-position players in order to cover for the loss of the recently retired Scott Thompson.

The Kangaroos used first-round NAB AFL Draft selections in successive years to snare Durdin at pick No.16 in 2014 and McKay at pick No.21 in 2015, though neither is yet to play more than 20 senior games throughout the start of their careers at Arden Street.

However, with veteran Thompson – one of the League's best intercept players over the past decade – retiring at the conclusion of last season, star defender Robbie Tarrant has forecast more prominent roles for the young pair in a new-look North Melbourne backline.

"They've been going really well," Tarrant told AFL.com.au.

"They've both been going well for a couple of years now, in my opinion.

"Before last year, Sam had a few injury troubles and when he finally got going he'd get injured. Ben had two really good years in the VFL and they're both going really well at the minute.

"They're training really well and that's all you can hope for at this time of year."

North Melbourne's defence was strengthened over the off-season by the signing of 85-game former Geelong and Brisbane defender Josh Walker as a delisted free agent.

It is also set to be bolstered further by the return of Majak Daw, who missed the entire 2019 season after suffering serious hip and pelvic injuries following a fall from a Melbourne bridge in December last year.

Tarrant, who was close to All Australian selection last season, is set to be a key figure in that much-changed backline. However, he believes the make-up of the eventual back six for the club's round one clash with St Kilda is still to be determined.

"It's changed a little bit," Tarrant said.

"I've probably played nearly every one of my games down back with Scott Thompson. But Sam, Ben, Josh and Majak … they're some guys that the club thinks will replace him.

"I'm sure it will pan out over the next couple of months to see what way we go."

Tarrant, who will turn 31 next April, is coming off another impressive season with the Kangaroos that was rewarded with a second-place finish in the club's best and fairest award.

However, despite Thompson's retirement, he does not believe there is any added weight on his shoulders to carry a younger North Melbourne backline next season.

"There's not necessarily any more responsibility," Tarrant said.

"At some point, we all just have to play our role. There are six defenders out there at a time, so we need to work in sync and get the job done."