James Stannard's hopes of a World Cup Sevens return have been dashed, with the veteran announcing his retirement on Saturday.

Stannard was planning on retiring at the end of the season, but his call has come sooner than planned after he was the victim of a tragic one-punch attack in March.

The hit left him with a fractured skull, and though he had held out hope of returning to the Aussie Sevens fold for July's World Cup, and had returned to training, but hasn't been able to recover enough to return to the team.

Stannard announced his retirement on Saturday afternoon, via Instagram.

"It is with great sadness that I'm announcing my forced retirement from rugby as a player due to head injuries I recently suffered," he wrote.

"It has been my greatest honour and privilege to have been able to pull on the " Green and Gold " and represent my country beside my mates, men I count as brothers over the past decade or so. The international rugby family have been so supportive and I'm humbled and thankful

"I want to thank my family, teammates, staff and opponents both here in Australia and around the world .

"It's been a fantastic ride , I've learnt so much and enjoyed every minute."

Stannard will bow out as one of Australia's most-decorated Sevens players, and the country's top World Series points scorer of all-time.

He has represented Australia in two Commonwealth Games, winning a bronze and silver medal in Delhi and Glasgow, and has played XVs, both with the Western Force in Super Rugby and in Japan.

Stannard's teammates were posting tributes to the playmaker on social media on Saturday night, lauding his influence on the game.