Australia fly-half Quade Cooper is expected to spend an extended period on the sidelines after suffering a "pretty serious" Achilles injury during the Wallabies' 41-26 win over Argentina in Mendoza on Saturday.
Cooper slipped while in possession seven minutes into the second half of the Wallabies' opening Rugby Championship clash before clutching his lower left leg and had to be helped from the field when he was replaced by Reece Hodge.
"We think it's an Achilles," Wallabies coach Dave Rennie told reporters after the game. "We'll get a little clarity around that, but it looks pretty serious."
The loss of Cooper, who returned to the fold last year after a four-year absence, comes at the end of a week that saw captain Michael Hooper return to Australia after informing management he was not in the right frame of mind to play.
Rennie, though, remains confident the Wallabies have talented options in reserve in the fly-half position to overcome the loss of the Japan-based Cooper.
"We've got James (O'Connor) and we've got Noah (Lolesio), so we've got a lot of depth in that position and that's the good thing about this group," said Rennie.
"We've got a lot of guys on the injured list but other guys step up and front up. Again, we won't look for excuses around that. The next guy who steps up has got to front for the jersey and the country."
Hodge made the most of his opportunity to impress Rennie, kicking one penalty and three conversions as the Wallabies impressed in the second 40 minutes to claim a bonus point win.
"Discipline wasn't good enough first half," Rennie said. "The pleasing thing was we were clinical in the second half and played the game at the right end of the field and built pressure.
"Losing Quade reasonably early in the second half just highlights the character of this group.
"Reece Hodge stepped up to play and the guys around him really stepped up as well and it was a hell of a second half."