His hamstring injury forced Cooper to withdraw from the starting line-up for the 2006 State of Origin series, being replaced by winger Eric Grothe, Jr. from the Parramatta Eels. After missing the first game of Origin for New South Wales, Cooper failed to be called up for game two with Grothe retaining his position after a solid performance in game one. On 11 June it was announced that Cooper had been called up as 18th man on stand by for the game.
His hamstring injury compelled Cooper to withdraw from the starting lineup for the 2006 State of Origin series, being replaced by winger Eric Grothe, Jr. from the Parramatta Eels. After missing the first game of Origin for New South Wales, Cooper failed to be called up for game two with Grothe retaining his position after a solid performance in game one. On June 11, it was announced that Cooper had been called up as 18th man on standby for the game.