Australia and Waratahs centre Berrick Barnes will take an indefinite break in a bid to overcome a debilitating 'footballer's migraine' condition that has plagued him throughout the Super Rugby season.
The 25-year-old ruled out of retirement, but is uncertain when he will make his return.
He still holds out hope he will be right for Australia's Wold Cup campaign which gets under way in September.
Barnes suffered a heavy concussion in the round two match against the Reds and has not been 100% since.
He has missed several games and was taken from the field during the win over the Highlanders on Saturday after complaining of nausea.
Barnes' absence for the rest of the season is a huge blow to the Waratahs' hopes of claiming a maiden Super Rugby title.
He will also leave a huge hole in the Wallabies' backline if forced out of the World Cup.