Melbourne Rebels may finish bottom of the Australian conference and the Brumbies will likely finish on top but the Rebels could claim their second win over the ladder leaders on Saturday night.

The Rebels beat the Brumbies 19-17 in Melbourne in April for their only win this season, yet the Brumbies are the favourites to go through to the Super Rugby finals.

This time the Brumbies have a lot more to play for as they enter the last three rounds of the campaign needing perhaps just one win and a loss from New South Wales to claim the conference.

The injury-hit Rebels lost star flanker Sean McMahon to a dislocated wrist last round and have 17 or so players on their casualty list, although Wallabies lock Lopeti Timani comes back into the side after a concussion.

Mitch Inman returns to the centres for the Rebels, while Reece Hodge moves to fullback and Ben Volovola to five-eighth.

Brumbies prop Ben Alexander is one game away from breaking his club's games record but will miss the Rebels game after injuring his knee.

Rebels coach Tony McGahan said his side knew it was good enough to claim another win over the Brumbies.

"This is a great opportunity for us to knock them over twice in the one year and show some resemblance of what could have been," McGahan said.

"To tour South Africa and Argentina and get two wins will mean the Brumbies come back with an unbelievable spirit and kick in their step.

"They know they are one win from going into the finals and going into June with things really settled."

Super Rugby pauses for the rest of June after this round as international rugby takes over and both sides boast a healthy number of Wallabies selections.

The Rebels were disappointed flanker Colby Fainga'a and outside back Tom English missed out on Wallabies places but both will play major roles in Saturday night's game.

Fainga'a will battle with another discarded Wallaby in Brumbies flanker Scott Fardy and whoever wins that contest will have a big say in which team wins.

McGahan said his side had to stand up to the Brumbies' attempts to dominate the breakdowns and set-pieces.

"The key to a Brumbies game, especially in Canberra, will be about the physical aspect of the game," McGahan said.

"They have a strong set-piece which has allowed them to keep in games and win games this season.

"They are clearly the most consistent side this season so they deserve that No.1 billing and to go onto the finals."