Latrell Mitchell has been ruled out of Wednesday's State of Origin opener in Adelaide after suffering a calf injury on Sunday.

According to reports, Mitchell pulled up early from a Blues training session at Sydney's Accor Stadium on Sunday night before playing down any concerns.

"I thought I'd give Nicho (Hynes) and Critta (Stephen Crichton) a run out there. I was a bit cold," he told reporters afterwards.

NSW assistant coach Paul McGregor similarly quelled any fears before the extent of his injury became clear.

"I just looked at him and he's got no ice. We've been swapping players in and out. The session was finished and we're doing a bit of kick-catch and he just stopped," McGregor said.

"For me, he's alright. I didn't see anything major. Everyone's got an issue at this time of year. We're 12 weeks in."

Mitchell delivered the news to teammates on Monday morning and will not travel with the squad to Adelaide.

The injury is understood to be minor and, at this stage, unlikely to rule the returning Origin star from game two in Brisbane on June 21.

It's a cruel blow for Mitchell, after ruling himself out of the 2022 series with injury.

NSW lost the series 2-1.

Panthers centre Stephen Crighton replaced Mitchell in the Blues' line-up after he was brought into the squad to replace Campbell Graham after he dropped from the squad shortly after teams were announced last week.

Mitchell has played 7 State of Origin games and scored six tries since debuting in 2018.