Stand-in Australian rugby sevens captain John Porch has suffered a leg injury just three weeks out from the first leg of the world series.
Porch was captaining an inexperienced Australian outfit at a warm-up Oceania Sevens tournament in Fiji, when he suffered the injury in his team's 43-0 win over the Solomon Islands.
The Olympian will undergo scans to discover the full extent of the injury.
Sam Caslick, brother of Australian women's player of the year Charlotte Caslick, will assume the captaincy for the remainder of the tournament.
The first leg of the men's rugby sevens series kicks off in Dubai on December 2-3, where Australia are aiming to improve on their fourth place finish in last year's championship.