LUKE McDonald is closing in on a new three-year deal with North Melbourne.

The Kangaroos defender was due to fall out of contract with the club at the end of this season, but AFL.com.au understands he will re-sign until the end of 2021.

McDonald has played every game this season and averaged 19 disposals as he continues to spend time on the wing. 

He has been a staple of North's line-up since joining the club as a father-son pick at the 2013 NAB AFL Draft, and is due to play his 95th game in Sunday's clash with Adelaide.

Serious talks on McDonald's contract extension didn't begin until later this year, with both the club and player believed to be happy to wait for more exposed form before settling on his value.

There was little doubt the 23-year-old would remain a Roo given his family history at Arden Street, where his father Donald played 155 games between 1982-92 and been a long-term member of its commercial department.  

"It was always going to be something towards the back end of the year that we could focus on," McDonald said recently.

"I've gone for North my entire life, so I can't see anything changing there."

He has shaped as one of the club's most important re-signings, with Jed Anderson remaining unsigned despite a career-best year.

The futures of veteran pair Jarrad Waite and Scott Thompson are unclear with the duo also out of contract as the end of the season edges closer, while Ben Jacobs, who continues to struggle with concussion symptoms, is also unsigned heading into the off-season.