Ireland's Olympic silver medallist Gary O'Donovan has been forced to pull out of the World Championships in Florida later this month.
O'Donovan, who won lightweight double sculls silver with brother Paul in Rio, has been suffering from a virus.
Paul O'Donovan will now be partnered by Shane O'Driscoll with Gary O'Donovan still travelling to the US as reserve.
The brothers gained a big following after giving a series of joyous interviews following their Rio success.
The O'Donovans' achievement earned Ireland's first ever Olympic rowing medal
The Skibbereen pair produced a brilliant performance to finish only 0.53 seconds behind French duo Pierre Houin and Jeremie Azou and they also took second behind the French boat at this year's European Championships.