Payne Haas remains no certainty to feature in the State of Origin opener after testing his injured leg to the side of the team's first Brisbane session.

The Blues, after a rain-hit week of preparation in NSW, descended on a sun-drenched Ballymore on Monday ahead of Wednesday's clash at Suncorp Stadium.

Broncos prop Haas, carrying a quadriceps injury suffered against St George Illawarra earlier this month, began the warm-up with his team.

But he was then ushered to the side for specialised fitness drills, testing his ailment before media were excused.

NSW officials remain confident barnstorming prop Haas will play, with Melbourne prop Stefano Utoikamanu on stand-by.

Murray Wenzel - AAP