Tomane and Nadolo will square off in a mouthwatering showdown of speed and power when the ACT Brumbies play the Canterbury Crusaders at Canberra Stadium on Sunday.

Just a few months later the two men leading Super Rugby statistics for clean breaks will move to France to join former Brumbies mentor Jake White.

White opened up the French war chest to secure the duo to lift Montpellier up the rankings for the 2016-17 season.

The Brumbies are still working with the Australian Rugby Union and Tomane's management in a last-ditch bid to try to keep him in Australian rugby beyond the end of the season.

But if he ends up moving abroad, French wingers will be trembling with fear at the thought of having to mark 130-kilogram giant Nadolo on one side and 101kg NRL convert Tomane on the other.

"Everyone knows how well Joey is playing, he's just on fire," said former Brumby Clyde Rathbone.

"It's a clash of different styles, and it's ironic that we're talking about Joey as the fleet-footed smaller winger in this one because he's not tiny.

"Probably the only time that will ever happen is if he comes up against Nadolo. I'm looking forward to it, it's a pretty good match of different wingers."

Tomane has scored five tries this season, including a hat-trick last weekend against the NSW Waratahs, and has made 19 clean breaks to lead the competition statistics.

Brumbies coach Stephen Larkham says Tomane is in career-best form, and the way he is playing is sending a reminder of how valuable he is to Australian rugby.

The man standing directly opposite him is one of the scariest prospects in world rugby and almost unstoppable.

Nadolo has made 15 clean breaks and scored three tries in Crusaders' superb start to the season, helping the competition heavyweight win their past six games in a row.

"Joey is certainly enjoying getting the ball in hand. There's a number of match-ups across the field and that's certainly one that people will be looking forward to," Larkham said.

"There's a number I'm looking forward to watching unfold. With Joey, I think he's just playing with a lot of confidence at the moment and it's showing in the best form of his career.

"There's no doubt [Nadolo] is quite big and can be difficult to stop, we had a chat about him in the team meeting but the focus isn't on the opposition, it's about us. We still feel we can improve."

Rathbone, who had a reputation as a hard-running winger, said the Brumbies must avoid falling into the trap of focusing on trying to bring down Nadolo.

The Crusaders are flying high despite New Zealand greats Richie McCaw and Dan Carter leaving at the end of last year.

The Brumbies haven't beaten the Crusaders since 2009, and only four players in their squad have tasted victory against Super Rugby's most successful club.

"The thing about Nadolo is he's actually quite skillful, he's not just about steam-rolling people," Rathbone said.

"You've got to stop him before he gets momentum. But when you're playing a team you haven't had a lot of success again, you can't make too much of one player. It used to be about Carter or McCaw, but they weren't the most influential performers. It will take a complete performance from the Brumbies."

Meanwhile, the Brumbies are giving injured flyer Henry Speight every chance to be available for Australian sevens selection for the Rio Olympic Games, despite fracturing a bone above his eye.

Speight has been ruled out of tournaments in Paris and London and is racing the clock to win a spot in coach Andy Friend's squad.

SUPER RUGBY ROUND NINE

Sunday: ACT Brumbies v Canterbury Crusaders at Canberra Stadium, 4.05pm. Tickets available from Ticketek.