Australian rugby sevens skipper James Stannard has been ruled out of competing in next week’s Commonwealth Games after an alleged one-punch attack in Sydney’s eastern suburbs early on Friday morning left him with a fractured skull.

In a statement, Rugby Australia said that Stannard was allegedly struck by a man after speaking with him outside a fast-food shop in Coogee.

Police have described the attack as “unprovoked”, and said Stannard did not know his alleged attacker.

Several members of the Australian men’s sevens team witnessed the incident and two of them, along with head coach Andy Friend, detained the man until police arrived, Rugby Australia said.

Stannard and the group, which included his teammates, team management and their family members, were out celebrating a farewell dinner for Friend at the Coogee Crowne Plaza.

New South Wales Police charged a 22-year-old British man over the alleged incident, which happened outside a kebab shop on Coogee Bay Road at about 3.10am.

Stannard, a Rio Olympian, was allegedly assaulted from behind and hit his head on the pavement. He was in a stable condition at St Vincent’s hospital and was conscious and talking.

Stannard was due to captain Australia at the looming Commonwealth Games on the Gold Coast, where rugby sevens matches will take place between April 13 and 15.

Rugby Australia is expected to provide an update on Stannard’s condition on Friday afternoon.

“He has a sore head,” police inspector Steve Egbers said, adding the incident “should never have happened”.

The area is a popular night spot in Sydney’s eastern suburbs and police believe alcohol was a factor in the alleged incident.

The British man was taken to Maroubra Police Station and charged with assault occasioning actual bodily harm.

He was granted bail and is expected to appear at Waverly Local Court on April 19.