Defending world champion Stephanie Gilmore is hoping to defy medical advice and compete in the next World Surf League event in Brazil.
Gilmore was forced to withdraw from the Margaret River Pro event in Western Australia last weekend after injuring a knee during a free surf.
The 27-year-old, who is chasing a seventh world title to equal Layne Beachley's record women's haul, said an initial X-ray after the incident had shown up a hairline fracture in her fibula which had caused her to withdraw.
An MRI undertaken in Perth on Thursday has cleared Gilmore of any ligament damage but bone damage is worse than initially thought and she could be sidelined for as much as six weeks.
"It showed multiple hairline fractures through the fibula and tibia around the fibula head and tibia plateaux, with some minor bone bruising around the kneecap and associated tendinitis," Gilmore said in a statement to AAP on Friday.
Despite the disappointing result, Gilmore says she hasn't ruled out taking part in the Rio Pro which is scheduled to start on May 11.
"I'm going to continue the rehabilitation process and hope things may move more quickly than expected to compete at the next event in Rio," she said.
Gilmore is third on the world rankings following the Australian swing of the tour.
The six-time world champion is 8700 ranking points behind championship leader Carissa Moore, after the American won the opening two events and finished runner-up in Western Australia.
Another American, Courtney Conlogue, moved above Gilmore into second on the rankings after winning the Margaret River Pro while two-time championship runner-up Tyler Wright is fourth, just 2400 points behind Gilmore.
If Gilmore isn't able to compete in the Rio Pro, the next event on the calendar is the Fiji Women's Pro from Cloudbreak, Fiji from May 31.
