Skelton is undergoing scans to determine the severity of the issue, having been named to start in the second row for Australia’s second Pool C encounter.
“At this stage, he’s still in the team,” Eddie Jones said at Friday’s team announcement, confirming that his captain had suffered “a knock”, and suggesting that he would give him until kick-off to prove his fitness.
The potential loss of Skelton could be a potential second heavyweight blow of the week to Jones with tighthead prop Taniela Tupou already out of the fixture having strained his hamstring.
The power-packed pairing have forged a potent scrummaging partnership on the tighthead side of the Wallabies’ scrum, which is growing in impact, and are significant parts of Australia’s attacking game as ball carriers.
Scrum half Tate McDermott, vice-captain, is also absent after suffering a head injury in the opener against Georgia.
Jones’s side got their tournament off to a winning start with a solid showing against the Georgians, but are all too aware of the threat posed by their opponents.
Fiji pushed Wales close but now their quarter-final hopes will be all but over if they are beaten at Stade Geoffroy Guichard.
With no Tupou, veteran prop James Slipper switches sides to start at tighthead, while Nic White replaces McDermott at scrum half.
“He’s like having a coach on the field,” Jones said of Slipper, Australia’s second most capped player.
“It’s a remarkable achievement to play in four World Cups. He started off as a tighthead and then volunteered to go to loosehead and he’s volunteering to go back to tighthead. It’s a real testament to his courage, to his resilience, to how much he loves the game. He loves playing for the Wallabies and we think on Sunday he will play a pretty big game for us.”
Fiji, meanwhile, have promoted Levani Botia and Josua Tuisova to their starting side.
The flanker and centre add plenty of quality to a team that nearly produced a stirring comeback against Wales, with scrum half Simione Kuruvoli and Tokyo 2020 gold medal winner Jiuta Wainiqolo also new starters.
“Obviously it was a pretty physical game against a good Welsh team,” said Simon Raiwalui, Fiji’s head coach. “The next day the boys were a bit sore.
“They recovered well, and mentally we were thinking that we’re onto the next task. The World Cup tends to turn around quickly in one week so we couldn’t dwell on the last match too long. We did our review and got out of it what we need to do better against the Wallabies. Obviously it’s a big challenge for us against a really good team.”