South Africa's Rosko Specman, right, leaps to catch Australia's James Stannard in a World Rugby Sevens Series tournament in Sydney. Picture: Rick Rycroft/AP

Sydney - Australia's sevens rugby captain James Stannard, who was to play in the Commonwealth Games, is in hospital with a fractured skull after being punched in an "alleged unprovoked assault", police and Rugby Australia said Friday.

The 35-year-old, who had been at a farewell dinner for outgoing head coach Andy Friend late Thursday, was allegedly "punched on the head" in the Sydney suburb of Coogee early on Friday, New South Wales state police said.

"As a result, he fell and struck his head on the pavement," police said in a statement.

Rugby Australia said two of Stannard's teammates Lewis Holland and Ben O'Donnell, as well as Friend, detained the alleged attacker -- a 22-year-old Briton -- until police arrived.

"The 22-year-old man who threw the punch then fled the scene, but was apprehended by witnesses until police arrived and placed him under arrest," NSW Police added.

Stannard was taken to a nearby hospital, where he remains in a stable condition and was "diagnosed with a fractured skull", the governing body said.

The British man, charged with assault occasioning actual bodily harm, was granted conditional bail on Friday and is due to return to court on April 19.

Stannard had been set to lead Australia's sevens team at the Commonwealth Games, which will be held on the Gold Coast from April 4-15.

It is not yet clear if he will still take part in the Games, with Rugby Australia saying on Friday it was working with police over the matter and would provide an update later.

Stannard was recently appointed skipper after injured captain Holland was ruled out of the Games.

Rugby Australia said in mid-March that Friend's contract, due to expire in July, would not be renewed.

Current women's sevens coach Tim Walsh, who is leaving his role after the Commonwealth Games, was selected as Friend's replacement.