State of Origin rugby league: Queensland coach Billy says Dane Gagai call the hardest to make

Ponga and Maroons stalwart Gagai were shock omissions for game one against the Blues to be played in Adelaide on May 31.

Broncos sensation Reece Walsh was preferred at fullback and Dolphins excitement machine Hamiso Tabuai-Fidow was named in the centres.

The axing comes after Ponga produced one of the great Origin performances in the series decider last season.

In his seventh Origin appearance, the marquee man was named man-of-the-match after an electrifying display in which he scored a try, made three line breaks and gained 262 attacking metres as the Maroons clinched the title with a 22-12 triumph at Suncorp Stadium.

Queensland traditionally adopt a "pick and stick" policy around team selection.

However, speculation about Ponga's position surfaced after he suffered a head knock early in the Knights' 26-6 loss to Cronulla on Sunday.

He passed a head injury assessment and went on to score the Knights' only try.

Ponga missed six weeks earlier in the season after a round two concussion and has suffered four concussions in the space of 10 months.

Asked if Ponga's history of head knocks and the potential for him to be a liability in the brutal Origin arena had been a consideration, Slater said: "There was no more influential player towards the outcome of last year's series than Kalyn Ponga. We take everything into consideration including that [duty of care]. Last year's performance is not just thrown out and we start again. That is certainly considered but it's not the be all and end all.

"The right decision for everyone involved. He has to play a bit more football. He has started that process.

"Reece Walsh has been playing fantastic football. I have watched him closer than most people and he is in a really good place."

Slater informed Ponga of his non-selection on Sunday night.

"I had to make some really tough phone calls," Slater said. "There were some good phone calls but there were some really tough ones.

"Speaking to Kalyn, speaking to Gags, Kurt Capewell, Xavier Coates ... they are tough phone calls. They are not easy decisions to make, but they are made for the right reasons."

Gagai has been a permanent fixture for the Maroons in the past eight series after making his debut in 2015. The 32-year-old was named player of the series from the wing in 2017 and has cult hero status north of the border.

However, a series of defensive errors against the Sharks counted against him. Prior to that game, his form had been exceptional for the Knights.

"That was the hardest phone call I had to make. We all know what Dane Gagai brings to the footy team," Slater said.

"Hamiso has been playing great too. Sometimes we focus on who is not there. Now is time to focus on who is there and building a game plan."