Spearhead Nick Larkey's huge contract extension allows North Melbourne to focus on the next stage of the club's build, interim senior coach Brett Ratten said.

Larkey, 25, turned his back on free agency to sign a new five-year deal that sees him commit to the Roos until at least the end of the 2029 AFL season.

"When you've got your key pillars in place, it allows you to structure up," Ratten said at Arden St on Friday.

"We know that we've got Nick for five years and hopefully more.

"We can build the team around him playing as the focal point in our front half, and it just allows us to add to it.

"We don't have to worry about that piece - that's done. We can move on to find someone else who can help and improve our footy club."

Selected with pick 73 of the 2016 AFL Draft, Larkey has kicked 156 goals in his seven seasons with the Kangaroos.

His four goals against the Giants last weekend took his season tally to 36, lifting him to fourth in the race for this year's Coleman Medal.

Asked if Larkey was the best pick 73 of all time, Ratten said: "He'd be close".

"He's a great late pick. They're the great stories in our game, about all the teams overlooking you and then you get your opportunity.

"It doesn't matter if you're pick one, 76, or a rookie … all you need is an opportunity to get on a list and play."