Latrell Mitchell has been ruled out of State of Origin II with a calf injury in a significant blow to a NSW side fighting to level the series at Suncorp Stadium.

Mitchell has been sidelined since suffering the injury during camp for the series opener but began running again over the long weekend, so was named at centre for the match in Brisbane on June 21.

But the Blues confirmed on Thursday afternoon he had succumbed to the injury, with Stephen Crichton set to replace him in the side as he did in Game I.

The Blues will release a statement on the injury on Thursday.