Luke Davies-Uniacke is poised to make an impact at AFL level as he shows more signs of the dominant clearance play that defined his stellar junior career, North Melbourne coach Brad Scott says.

Scott also told AFL.com.au this week talented defender Luke McDonald was ready to rebound from a disappointing 2018 after taking his fitness to a new level this summer.

Davies-Uniacke played five of the first six rounds in his debut season but just two games thereafter as he spent the rest of 2018 working on his game in the VFL.

Scott told AFL.com.au the good form of North's more experienced midfielders had played a large part in Davies-Uniacke's extended VFL stint last season, but said the former Dandenong Stingray, like many first-year inside on-ballers, had also found competing against seasoned AFL players a huge step up.

"Luke Davies-Uniacke as a junior was a big powerful midfielder who was really able to dominate his opposition at a similar age," Scott said.

"When you come into the AFL as a genuine inside midfielder – and Luke was a big 18-year-old – you're still a boy against men.

"So I think that has been the challenge for him and one that can only be solved through time and opportunity.

"Luke through the pre-season has started to show a lot more of the signs and the passages of play that we saw from him as a junior.

"Now he's stronger, he knows what the AFL system is all about. He knows the standard that he's got to rise to and he's been a really pleasing performer over the pre-season."

McDonald, 24, is entering his sixth season after an up-and-down 2018 campaign he later labelled as "disappointing".

The defender was one of the standout performers in North's intraclub game at Arden St on Wednesday, and looked noticeably leaner.

Scott said McDonald was poised to reap the benefits of a "mature" approach to his 2019 pre-season.

"He was a very capable junior who just used to show up and perform. That's certainly not a question over his professionalism – he's always been a really hard trainer – but he understands now what's required to produce up to his capabilities over the long-term," Scott said.

"While he's looking sharp and he's certainly fitter than he's ever been, it's amazing the flow-on effect that has had on his skill level and his cleanliness with his hands.

"You wouldn't think getting fitter helps those things, but it certainly does at this level."

Meanwhile, the timeframe on Ben Jacobs' return to the field remains unclear after his cursed run over the past three seasons.

The run-with midfielder starred in the first half of 2018 after returning from nearly two years on the sidelines with foot injuries but played only one game after round 12 as he battled lingering concussion-like symptoms that were eventually diagnosed as chronic sinusitis.

Following post-season surgery, Jacobs has completed a good volume of training this summer, but is still experiencing "a bit of congestion and general grogginess".

Scott was unsure whether Jacobs would play in next month's JLT Community Series, saying North was determined to ease him back into games.

"Clearly, as coach, I'd love to have him out working with our other midfielders in our intraclub practice game and JLT games, but our focus is making sure Ben's available for as long as possible this year and we just don't want to risk that," the Roos coach said.

"We think we can get the best of both worlds, by giving Ben as long as possible to feel perfect again while still getting a high volume of work into him.

"He's not feeling 100 per cent in terms of his nose and sinus, but we're assured that will run its course, it just takes time.

"Certainly we wish it was quicker, but we're confident we're on top of it."