Kidney has faith in Murray
Conor Murray will make his full Test debut when Ireland open their World Cup campaign against the USA on Sunday.
Murray, who at 22 is the youngest member of the squad, won his two caps as a second-half substitute against France and England last month. Murray only broke into Munster's first team this year but he did enough in the warm-up Tests and during his time in camp this summer to secure a place alongside Jonathan Sexton at half-back, with Eoin Reddan dropping to the bench.
"Conor's been going well in training and we said we'd judge it off that. If we're to know more about him, now's the time to know," said Kidney.
"He deserves a go and we think he's good enough to start. It's a big call given it's our first game in the World Cup, but what he's been doing merits his inclusion."
Flanker Sean O'Brien and full-back Rob Kearney have been omitted from the 22 as a precaution. The Leinster duo have been passed fit from their respective knee and groin injuries but Kidney, mindful of the clash with Australia next Saturday, has given them another week to recuperate.
Geordan Murphy will continue at full-back while Shane Jennings will slot in at openside.
"Sean is fit to play, medically he has been given the okay. But I've seen injuries like that before and he'll benefit from getting absolute fitness back," said Kidney.
Gordon D'Arcy is restored at inside centre having recovered from the calf injury which delayed his arrival in New Zealand.
The most unfortunate member of the squad is Andrew Trimble, who is demoted to the bench despite being Ireland's most dangerous player during last month's warm-up internationals.
Tommy Bowe and Keith Earls have been named on the wings and Trimble will feel a sense of injustice at his exclusion.