St George Illawarra will be without Josh Dugan for at least five weeks after the star fullback underwent surgery on his injured elbow.
Dugan suffered a hyper extension to his elbow against South Sydney a fortnight ago.
The 25-year-old was then selected in the NSW Origin team and was confident of overcoming the problem in time for Origin I.
But a training mishap on Saturday aggravated the injury, which will now require surgery.
Dragons head of medical and performance Tony Ayoub said the elbow had now become locked due to fragments floating in the joint.
Dugan will undergo an arthroscope and be unavailable until the round 17 game against Manly on July 4 at the earliest.
Meanwhile, St George Illawarra have confirmed the signing of Newcastle forward Tariq Sims on a three-year deal starting next season.
There are reports the 26-year-old former Junior Kangaroo will link with the Dragons immediately, though neither St George Illawarra or Newcastle have confirmed the deal.