Their 23-point win against the Japan Sunwolves has put them on the cusp of a return to the Super Rugby play-offs after missing out last season.

But Speight's potential calf injury will have Brumbies fans on edge as the "bro with the fro" waits to see if injury ends his time at the club.

The good news from coach Dan McKellar? "They're looking at his calf. The initial thought was it was a cork. But nothing serious, we'll wait and see," McKellar said.

Speight was at his damaging best in the first half and helped set up a try for Tom Banks, but he returned in the second half with strapping on his knee and them bowed his head and left the field three minutes after the break.

Speight has signed a deal to join the Queensland Reds next year and the cult hero's impending exit has devastated Brumbies supporters. Ending on injury would be a bitter pill to swallow.

It's time for everyone in Canberra to embrace the rolling maul. Brumbies captain Christian Lealiifano decided to on Saturday and lending his flyhalf weight to help his side score three pushover tries.

The rolling maul could be the Brumbies biggest weapon for a title tilt. Opposition teams fear it, especially after seeing replacement hooker Connal McInerney go over for a second-half hat-trick against the Sunwolves.

"We all talk about the rolling maul all the time," said Wallabies legend Tim Horan on Fox Sports.

BRUMBIES NEWS

"We get sick of talking about it. But it's a real weapon for the Brumbies and they know how to use it now.

"They don't overuse it. They scored three tries from it, but they spread the ball wide and I like the way Christian Lealiifano has really matured as a player."

Little moments can make or break championship dreams, and if Super Rugby officials are smart they'll make sure referee Federico Anselmi doesn't have to make those calls in big games.

Anselmi was off the pace at times, missing clear knock-ons plenty of breakdown infringements.

Brumbies coach Dan McKellar said: I thought there were some blatant knock-ons missed, which didn't help.

"Our discipline hurt us at times as well, but I'm really pleased we came here and got the five points we were after."

It's tight, but the Brumbies are one win away from Super Rugby finals glory and earning the right hosting a play-off at home.

The Brumbies will play the NSW Waratahs and the Queensland Reds in the last rounds of the season.

They are on 39 points, five ahead of the Melbourne Rebels and nine ahead of the Waratahs with the top team automatically qualifying for finals.

The Rebels will play the Waikato Chiefs and Canterbury Crusaders. The Waratahs have the Brumbies then the Otago Highlanders.

The Brumbies have by far the better run to the finals, but stranger things have happened in Super Rugby land.

There have been so many comings and goings this week, it was always going to be easy to miss one. So in between David Pocock, Lachlan McCaffrey, Henry Speight and Matt Lucas, prop Les Leuluaialii-Makin made a decision as well.

The pocket rocket front-rower is set to join Japanese second division club the Kurita Water Gush after the Super Rugby season.

AT A GLANCE

ACT BRUMBIES 49 (Connal McInerney 3, Pete Samu, Irae Simone, Tom Banks tries; Christian Lealiifano 7 conversions) bt JAPAN SUNWOLVES 19 (Hosea Saumaki, Semisi Masirewa, Jamie Booth tries; Hayden Parker 2 conversions) at Prince Chichibu Stadium, Tokyo. Referee: Federico Anselmi.