Former Wallabies hooker Brendan Cannon isn't backing away from his pre-season prediction that the Rebels will finish bottom of the Super Rugby competition.

On Saturday night the Rebels face the Western Force, where Cannon was a foundation player.

Picking the Force to bounce back from their 51-16 loss to South African front-runners, the Stormers, Cannon said the wild inconsistency of the Rebels was their downfall.

Of the six rounds of competition they have won two matches - the last a rousing 42-25 win over the Hurricanes - and were unlucky in a third, while they have also delivered three shockers.

"I think the biggest challenge they've got is that the variance between a good and a bad performance has just been so extreme," said Cannon, now a television commentator.

"I'm sure even the coaching staff wouldn't know what side's going to turn up on a game day basis.

"Their performance week to week has just been so erratic."

He put the inconsistency down to the mixing pot of internationals in the line-up, injuries to key players, and just being a new side in general.

Before Melbourne's debut match earlier this year the 42-Test veteran said the side would be unlikely to top the Force's inaugural season performance of just one win.

While the record books show they have already done that, Cannon still believes the early Force was a better side.

"They have won more but the Force never really suffered the blow-outs that the Rebels have.

"The losing margins were far less so you could say the Force were more competitive, albeit only winning one game."

Cannon, who also played for Queensland and NSW, said a positive to come from the Rebels was the opportunities afforded to players such as exciting young halfback Nick Phipps.

"He was really impressive against the Hurricanes and he's certainly a player of the future," he said.

Brought to you by AAP © 2024 AAP