Sydney - Samu Kerevi and Nick Phipps are out of the three home Wallabies Tests this month with injuries suffered in Super Rugby, the Australian Rugby Union said on Sunday.
Centre Kerevi injured an ankle during the Reds' 34-29 loss to the Blues in Samoa on Friday, but will not require surgery, an ARU statement said.
Waratahs scrumhalf Phipps has also injured his ankle and returned home from New Zealand where the Waratahs lost 46-31 to the Chiefs on Saturday.
Australia have called up uncapped scrumhalf Jake Gordon and his Waratahs team-mate Rob Horne as replacements.
"It's really unfortunate for Samu and Nick, but a great opportunity for Jake and Rob to come into the squad," Wallabies coach Michael Cheika said.
"Jake was involved in our camp earlier this year and has really stepped up for the Waratahs in Super Rugby.
"Rob has been a strong leader in our Wallabies environment and his experience will be invaluable."
Australia kick off this month's domestic Tests against Fiji in Melbourne on Saturday followed by internationals against Scotland in Sydney on June 17 and Italy in Brisbane on June 24.