Newcastle's Bradman Best will replace the injured Latrell Mitchell in the centres for State of Origin III, and the Warriors' Mitch Barnett has been named to debut off the bench in place of Haumole Olakau'atu.

Best was the logical replacement for Mitchell. He was the incumbent after his debut in Game III last year and likely would've played this year's opener if not for an untimely hamstring injury and the other options his time around all had marks against them.

Tom Trbojevic looked well off the pace in his return from a hamstring injury for Manly last night, Joseph Sua'ali'i hasn't played since being sent off and suspended after Origin I, and Matt Burton is a completely different player — more of a playmaker than the powerful ball-runners Maguire seems to be looking for.

Barnett, meanwhile, has been in camp for the first two games and can play in the middle and on an edge.

No word on why Haumole Olakau'atu has missed out, but there hasn't been anything said about injuries to him.

The extended 20-man squad will be finalised on Monday.