Like most of his Wallabies teammates, Super Rugby AU grand final star Lolesio had an evening to forget in Saturday's 43-5 drubbing by the All Blacks, which ensured New Zealand retained the Bledisloe Cup for an 18th straight year.

He'll likely be replaced by James O'Connor in the dead-rubber fourth Test on Saturday, the with the Queensland veteran expected to be fit after missing the last match with a knee injury.

But Seib, who has signed a two-year contract with the Brumbies, believes Saturday's baptism of fire was just the beginning of a prosperous international career for Lolesio.

"If you ever want to make a tough debut, it's against the All Blacks isn't it, he was certainly put under pressure but I know a guy like Noah...he'll learn and grow and be better and better for the experience," Seib said.

"He's a courageous player. [That's] the thing I like about tens who aren't afraid to have a go, he's not conservative whether it's kick pass run he's got that triple threat.

"For him going forward that's probably the most exciting thing from my perspective, is that he's prepared to have a crack when opportunities arise."

Seib joins the Brumbies after a stint in charge of the Queensland Reds Academy, and also coached Queensland Country for their past two National Rugby Championship campaigns.

He replaces Peter Hewat, who left for Japan following the Brumbies' Super Rugby AU triumph after three years overseeing the club's attack.

For Seib, who has worked with Lolesio at Schoolboy level, joining McKellar's coaching staff was an opportunity too good to pass up.

"They've had a tremendous amount of success, they're known as a world class operation," Seib said.

"When I got a phone call from Dan, it was quite an easy decision after we sat down to discuss what I could potentially offer. All in all, it was a no brainer.

"There's a backline group that's got a lot of talent, there's a lot of youth coming through as well. Whilst you've got some top end Wallabies there, there's also a lot of guys coming in behind them.

"Coming off the back of the success of the Super AU, it's an exciting opportunity for me to work with such a talented group."

MORE CANBERRA SPORT

And despite Saturday's dismantling by the All Blacks, Seib was confident the gap between the two nations was closing.

"Before COVID shut [Super Rugby] down, the results the Brumbies were getting and the success they had against New Zealand teams I think showed we are bridging that gap," Seib said.

"There's going to be bumps along the road, obviously the Wallabies Test on the weekend is one of those bumps. There will be the odd setback but when you're playing the best team in the world week in week out you're going to have those bumps.

"I can see over these next few years, teams like the Brumbies leading the charge and closing that divide between the two countries."