Sam Burgess's arrival at Bath has been delayed after he had a metal plate inserted in his face following his injury in the NRL Grand Final.
Burgess, 25, was hurt after six seconds of the match, his final league game before switching codes, but played on to help South Sydney win the title.
The surgery on his fractured cheekbone and eye socket took place on Tuesday.
Burgess was due to arrive at his new union club on 15 October but Bath are now unsure when he will fly to England.
Head coach Mike Ford told BBC Points West: "He'll come out of hospital and the surgeons will have to sit round a table with the South Sydney doctor, and then communicate to our medical team when he can fly over and how long he'll be out for."
Burgess has signed a three-year contract at Bath and has been touted for a place in the England squad for the 2015 World Cup.
He played in the forward pack for the Rabbitohs, but is expected to feature at centre in the 15-man code, and Bath had hoped to give him his debut in the LV= Cup in November.
The Dewsbury-born England and Great Britain international left Bradford Bulls and moved to Australia for the start of the 2010 NRL season.
Sunday's 30-6 Grand Final win over Canterbury Bulldogs earned the South Sydney Rabbitohs - co-owned by film actor Russell Crowe - a first NRL title in 43 years.
Despite his injury, Burgess went on to become the first non-Australian to win the Clive Churchill medal for the man of the match.
"I knew he wouldn't come off because he's a tough guy," continued Ford. "But I knew he'd done something serious as he got up from that first tackle and pointed to his cheekbone.
"It's a blessing in a way, I think. We were always going to give him time off when he came over. We've now got the comfort that we can't play him anyway.
"We were only ever going to play him when he was ready. We weren't going to push him out there when he doesn't know the laws of the game."