Cleary copped the most brutal blow of the State of Origin series opener in the form of friendly fire from teammate Tom Trbojevic midway through the opening stanza.

It left the Penrith No.7 needing five stitches on his right cheekbone, requiring him to be interchanged just before halftime.

Under the NRL's guidelines, players who have blood on them are required to be taken out the back of play and be treated and cleaned up.

Play was then stopped a second time around, meaning Cleary was ordered to leave the field by referee Gerard Sutton to be cleaned up under NRL rules.

The incident cost the Blues two interchanges as they decided to replace him with Jack Wighton rather than play a man down while the playmaker sought treatment.

An NRL official has since confirmed to AAP the process was correctly followed.

Cleary's jersey also had faded blood on it throughout the second half, with NRL guidelines stating it must be treated with detergent and bleach before returning to the field.

Cleary was still sporting a significant black eye on Thursday morning, wearing it as a badge of honour after the Blues' 50-6 flogging of Queensland.

"I've never really been cut like that. But for the first time I'm pretty happy it's in Origin," Cleary said.

"When the ref told me to go off (and get cleaned up the first time) I thought it would be sweet.

"Obviously it didn't stop bleeding. It ended up costing two interchanges but I got stitched up at half-time and it was alright.

"It's obviously swollen and swelling up this morning but it feels fine."

Cleary's blow did little to dampen his impact, with the blood on his jersey making him easily the best player on the field with anything close to red on his clothing.

He set up three tries in the win and halves partner Jarome Luai one, as the pair answered questions whether they could bring their Penrith style of play to Origin.

"Nathan asked me how I felt and I just said: 'I'm sweet brah. Let's go get it'," Luai said.

"He knows how I feel. That's all he needs to say, he was just checking up on me.

"I think he knew deep down I was going to go out and whatever he done I was going to have his back."

Australian Associated Press