Wallaby reserve halfback Chris Whitaker remains in doubt for the Tri-Nations trip to South Africa, unable to train because of a hip problem.

A stiff and sore Whitaker limped badly as the Wallabies completed a heavy session as they continue their build-up for the Tri-Nations rugby opener in Cape Town on July 12.

Utility back Matt Giteau, who ran for the first time on Thursday after recovering from knee fractures, remains on standby.

Whitaker had an MRI scan on Wednesday, which revealed a permeated disc in his lower back, and inflammation of muscle deep in his hip.

He has been battling the problems for some time now, which caused pain each time he tried to sit.

The back problem responded to treatment and the NSW halfback was hoping a cortisone injection would ease his hip by Friday.

Wallaby doctor Martin Raftery will put Whitaker through a medical check again on Friday.

Whitaker was still hopeful he would be on the plane to Cape Town on Saturday.

"I'm going to try and run (on Friday) and hopefully do the training," the 28-year-old said.

"I'm hoping the cortisone kicks in. It feels better than it has, and I only really feel it when I've been on it for a while."

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