James Tedesco has failed to return for the second half of the State of Origin decider in Brisbane after a head clash in an eventful final minute of the first half.

The NSW fullback clashed heads with Queensland's Briton Nikora, who was carrying the ball after a Blues knock-on.

Trailing 18-4, Nikora stopped and stared down a dazed Tedesco before playing on and being tackled, triggering an all-in scuffle.

Tedesco was taken for a HIA, which he failed at halftime and was replaced by Tolu Koula.

Nikora was placed on report for high contact in the ensuing scuffle, the full house not impressed when referee Ashley Klein awarded a penalty to the visitors.

"Well he's pretty excited but he knows he's got a big job because they'll look to target him," NSW coach Laurie Daley said when asked what he said to Koula.

The Maroons were then forced into a second-half change of their own, Reece Walsh injected when halfback Sam Walker was also sent for a HIA after slipping into teammate Robert Toia.