Isaiya Katoa's red-hot form has caught the eye of the NSW selectors, with the Dolphins halfback invited into the Blues camp ahead of the State of Origin decider in Brisbane.

While the 21-year-old is not expected to feature in Game Three, the invitation signals a growing belief that Katoa is a serious long-term prospect for the sky-blue No. 7 jersey.

NSW coach Laurie Daley extended the offer as a development opportunity and to give Katoa a look at the elite representative environment.

The Blues are managing a few concerns in the halves, with Nathan Cleary still carrying a groin complaint and Jarome Luai returning from a recent infection, but both are expected to be fit for the series finale.

Katoa's inclusion comes after another commanding performance in the Dolphins' 50-28 demolition of South Sydney.

The playmaker chalked up four try assists and three linebreak assists as Kristian Woolf's side continued their mid-season surge.

It marked the third time in four games the Dolphins have posted 50 points, a remarkable feat considering the absence of key forwards like Daniel Saifiti, Thomas Flegler, Tom Gilbert, Max Plath and Felise Kaufusi.

In that time, Katoa has piloted the side to four wins from their past five matches, all by scoring 44 points or more. His mix of composure, vision and ballplaying instincts has impressed pundits across the game.

The official NSW squad will be named on Sunday night, with Katoa's camp role expected to be confirmed then.