Skipper Stirling Mortlock will be a surprise spectator when star recruits James O’Connor and Kurtley Beale make their Melbourne Rebels debuts in Geelong on Friday night.

Mortlock is a late withdrawal from the Rebels backline where he was set to partner O’Connor in the centres for part of the opening pre-season trial against the Waikato-based Chiefs.

The former Wallabies captain will be sidelined with a minor knee injury which has failed to improve following a training knock a week ago.

Mortlock’s absence hampers plans to gel new combinations with O’Connor running at inside centre and Beale at fullback together in the second quarter among what appears a full-strength backline.

But new coach Damien Hill is unfazed by the need to take a cautious approach by resting the 80-Test centre.

“It’s nothing serious but you don’t want to rush these things,” Hill told AAP.

It gives former Wallabies and Reds centre Lloyd Johansson more of a chance to shine at outside centre in his return to Australian rugby.

Controversial English import Danny Cipriani has been named at five-eighth for the first half and most interest will be on his combination with O’Connor in the second quarter.

Beale has defied his lingering hamstring problem to line up at Simonds Stadium but Hill isn’t putting any pressure on his two Wallabies recruits.

“It’s a combination of just getting a little bit of game fitness for the both of them and more importantly getting combinations overall,” he said.

Hill stressed he had no pre-conceived ideas over who to play at No.10 when the Super Rugby competition kicks off but had been impressed by Cipriani’s work ethic.

“If his training performances are any indication he’s in a good spot at the moment so we can’t really ask more of him.”

Utility back Richard Kingi has been an impressive pre-season performer and can throw down a challenge to Wallabies back-up halfback Nick Phipps when he plays the first half at No.9.

The Chiefs will feature All Blacks five-eighth and former Hurricane Aaron Cruden in his first match since the World Cup final when he hyperextended his right knee.

Sonny Bill Williams was left out of the visitors’ 29-man squad due to his New Zealand heavyweight title bout against Clarence Tillman III in Hamilton next Wednesday.