Australia scrum-half Jake Gordon had surgery on a torn Achilles Monday, ruling him out of the three Nations Championship tests next month.
The 32-year-old went down clutching his right leg in the first half of the Waratahs final Super Rugby game of the season on Saturday – a 31-25 loss to Western Force in Perth.
"The Waratahs can confirm Jake Gordon successfully underwent surgery on a torn Achilles this morning," his club said.
"The scrum-half will be sidelined for a significant period and will miss the Wallabies' upcoming Nations Championship campaign."
The Wallabies start their year against Ireland in Sydney on July 4 in the inaugural Nations Championship before meeting France a week later in Brisbane then Italy in Perth.
They will then have back to back tests against Japan, away on August 8 before hosting Eddie Jones's side a week later.
Tate McDermott and Ryan Lonergan are in the running to replace Gordon, who has been Australia coach Joe Schmidt's preferred starter.
Playmaker Kurtley Beale suffered a similar injury in June 2024 and it kept him out of the Australia team for close to a year.