LAUNCESTON, AUSTRALIA - AUGUST 13: Aaron Mullett of the Kangaroos controls the ball during the round 21 AFL match between the Hawthorn Hawks and the North Melbourne Kangaroos at University of Tasmania Stadium on August 13, 2017 in Launceston, Australia. (Photo by Robert Cianflone/Getty Images)

Carlton has thrown defender Aaron Mullett a lifeline, securing the services of the 25-year-old former Roo as a delisted free agent.

Mullett arrives after playing 85 games over seven seasons at North Melbourne. He was taken at pick 34 in the 2011 Rookie Draft.

The 25-year-old enjoyed a career best year in 2013, playing every game and averaging 19 disposals, 3.6 rebound 50s per game.

But he could not keep that level of performance up as injures hurt his form and he fell out of favour with the coaches.

He looked to finally be finding his feet again at senior level this year but was told last month he was surplus to requirements, despite playing 33 games over the last two seasons.

Blues list manager Stephen Silvagni said Mullett was a valuable addition to the their list.

"We're very pleased to give Aaron another opportunity at AFL level, one we know he will fully embrace," Silvagni said.

"An impressive contributor for North Melbourne's backline, Aaron showed his talents as an effective rebounding defender. However recently, he has also been pushing through the middle so we see some exciting versatility there.

"Importantly for our young group, Aaron provides valuable experience after seven seasons at senior level. With a strong pre-season campaign, we're confident Aaron will be in a position to cement a regular spot in our senior side in 2018.

"After another 13 list changes following the end of the 2017 season, our list is continuing to take shape and we'e excited about Aaron joining the ranks under coach Brendon Bolton and his team."

Mullett plays predominantly across half-back, but had been deployed on the wing at times for North.

His average of 5.6 rebound 50s per game in 2017 was enough to place fourth in the league, just behind new teammate Sam Docherty.