Butler is one of several Brumbies who will leave Canberra in the coming weeks after they were knocked out of the finals on Friday night.

Coach Stephen Larkham has also finished his tenure, with Dan McKellar to step into the role as his successor.

The Brumbies are yet to finalise their full squad for next year with some players still weighing up their future and others trying to negotiate new contracts.

But Butler, Scott Fardy, Tomas Cubelli, Jordan Smiler, Tom Staniforth and Saia Faingaa have signed deals to leave the capital.

The Brumbies are still hopeful fullback Aidan Toua will be able to re-sign with the club, despite agreeing to play in Japan in the off-season while Chris Alcock is also set to move to Japan.

Butler will join Irish club Connacht, admitting it was hard to walk away from the Brumbies after their finals hopes crashed against the Wellington Hurricanes.

"After the game a couple of the boys were shaking my hand saying, 'it was nice playing with you'," Butler said.

"That's when it hit me a bit. It kind of sucked. I think I'll get pretty emotional when I sit down and talk about it.

"I've really loved it in Canberra, it's such a good rugby community and I've got some very fond memories.

"But there are some young guys coming through and the culture down here is a big part of that. Players can come and go, but the culture sticks around.

"When you've got a guy like David Pocock coming back and [forwards coach] Laurie Fisher ... the stars will align."

A host of Brumbies will be called into the Wallabies squad this week after claiming another Australian conference title.

The Hurricanes beat the Brumbies 35-16 in a quarter-final battle at Canberra Stadium, inflicting more pain on Australian rugby after losing all 26 trans-Tasman derbies this year.

New Zealand sides have won the past 32 games against Australian Super Rugby sides and the All Blacks have dominated the Wallabies for more than a decade.

But the Brumbies are confident they can build belief to end the streak after leading at half-time and threatening to knock out the defending champions.

The Brumbies lost seven games by seven points or less, including three against New Zealand teams.

"We were confident with our squad ... we showed that if we can hold that intensity for 80 minutes, the future's bright for us here," said Wallabies prop Scott Sio.

"The great thing about it is that we're keeping a lot of the youth here, everyone's going to be that one year wiser and if we do get an opportunity again to play some finals rugby everyone's had that little bit of a taste and we'll be ready for it."

Larkham will become a full-time Wallabies assistant coach, but will still work with the Brumbies on a consultant-style basis.

"We've had a focus to beat New Zealand sides over the last couple of years ... we set about getting a game plan to beat them because they all play a similar style," Larkham said.

"It's pretty difficult to think about the seven games we lost by seven points, but the focus is the same. We have to play New Zealand sides so we have to make sure we're better at it next year."