Four months after being sent home from South Africa in disgrace, Wallabies youngster Matt Henjak has been anointed as George Gregan's halfback successor.

Henjak has displaced the unfortunate Chris Whitaker, Gregan's faithful long-time deputy, from the Australian reserves bench for Saturday's Test against Ireland at Lansdowne Road.

The 23-year-old is one of four changes to the Wallabies' team, with rookie props David Fitter and Greg Holmes given the huge task of transforming the struggling scrum in their starting debuts while Wendell Sailor is recalled on the bench.

For Henjak, coach Eddie Jones' surprise decision marks a dramatic turnaround after he was thrown out of the tour to South Africa in July for misbehaviour in a Cape Town nightclub.

Jones on Thursday praised the professionalism and maturity shown by Henjak since that incident.

"It's been excellent, absolutely excellent, and good things come out of unsavoury episodes and certainly South Africa was a low part of his career," Jones said.

"He's worked very hard to get himself right and that's another reason why we're giving him an opportunity."

Showing the Wallabies selectors feel it's time to bite the bullet two years out from the World Cup, Jones said there were no problems with Whitaker's tour form and he deserved better.

"It's going to be very difficult (to tell Whitaker)," he said.

"Certainly he's undeserving of this demotion but we just feel it's time to give Henjak a bit of a show."

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