Queensland halfback Cooper Cronk has broken his arm in the opening exchanges of State of Origin I.

Queensland halfback Cooper Cronk has broken his arm in the opening exchanges of the State of Origin series-opener at Suncorp Stadium.

Cronk suffered the injury in a tackle on NSW second-rower Ryan Hoffman and was replaced by Daly Cherry-Evans in the 10th minute on Wednesday night.

The Blues also appeared to suffer an injury blow when Brett Morris scored a try to level the game at 4-4 in the 19th minute but the winger returned to action after treatment to his shoulder.