Brumbies scrum-half Nic White has been ruled out of Saturday's game against the Melbourne Rebels with an ankle injury.
White was initially named on the bench as the Brumbies looked to freshen things up following last week's loss to the Blues, with Michael Dowsett getting the start.
Injuries are beginning to hamper the Brumbies' campaign with Matt Toomua, Tevita Kuridrani and Joe Tomane already sidelined, while White is now set for three weeks out.
Joe Powell, who has only had two training sessions with the Brumbies, is set to take White's spot on the bench.
"We weren't sure whether [White] would be right for the game, we'll rest him this week," Larkham told the Canberra Times.
"Joey Powell comes out of club rugby … I'm looking forward to seeing how he goes. We planned this was the week to give [Dowsett] a start.
"We weighed it up knowing we had a number of injuries and changes … the Rebels can sniff [a weakness] if they want to, but we're just focused on a good performance."