SYDNEY, Aug 3 (Reuters) - Australia were dealt a blow ahead of Saturday's Rugby Championship decider against old foes New Zealand after lock Rob Simmons was ruled out of the Sydney showdown because of a wrist injury.
The 26-year-old Queensland Reds second row will undergo surgery for a scaphoid injury but should be fit to play in the World Cup warm-up against the United States in Chicago next month.
"Obviously we're all disappointed to lose Rob," Wallabies coach Michael Cheika told reporters in Sydney on Monday.
"We've been able to build some real depth in the lock position, and Rob's injury presents an opportunity for another player in the squad to stake their claim."
Former skipper James Horwill is in line to replace Simmons, who has won 52 caps, and become the lineout caller for the Wallabies.
Simmons is also unavailable for the return Bledisloe Cup fixture in Auckland next week but there are no concerns he would miss the Sept. 18-Oct. 31 World Cup in England where Australia have been drawn with the hosts, Wales, Fiji and Uruguay.
A 24-20 victory over South Africa in Brisbane and 34-9 win in Argentina last month have set Australia up for a first Rugby Championship title since 2011 and buoyed hopes of a third World Cup triumph.
Cheika said that back Matt Toomua and prop James Slipper would need to come through Tuesday's training session before being cleared to play in Saturday's clash in Sydney, but utility back Matt Giteau was available after missing the Argentina test. (Writing by Patrick Johnston in Singapore; Editing by Peter Rutherford)