Newcastle halfback Jarrod Mullen will miss two to three weeks with a torn calf muscle, virtually ruling him out of Origin II for NSW at Telstra Stadium on June 13.

Knights officials on Wednesday confirmed the worst, with Mullen suffering a two centimetre tear in his troublesome right calf muscle and unable to play for at least two weeks.

"It's a two to three week injury we think," said Knights media manager Stephen Mount.

"We're not sure where it places him with Origin."

With the NSW team to be named on Tuesday, Mullen is walking a tightrope to retain his spot in the Blues squad.

Since his Origin debut at Suncorp Stadium last week, Mullen has only played in the record 71-6 drubbing from Brisbane and would be low on confidence after two losses from a pack of Queenslanders.

While selector Laurie Daley on Tuesday confirmed Mullen "doesn't have to play" on the weekend to be chosen for the Blues, NSW would be hesitant to gamble on the halfback's fitness and inability to train for most of the preparation.

Mullen, 20, however said he would not risk his ongoing fitness by trying to rush back for NSW.

He said he would not push himself to play against the Sydney Roosters at Gosford on Saturday night even if it cost him his sky blue jersey.

"I have heard a lot of rumours that they're not going to pick me if I don't play this week," Mullen told the Nine Network.

"I'm not feeling pressure to play this week. I don't want to do any more damage to it.

"I will do the right thing and pull out if I'm not right."

Daley said the calf injury was likely to be the only thing preventing Mullen from retaining his spot, as he had little doubt the young star could overcome the beating his confidence has taken over the past two games.

"He is not confident as cocky as such, but he has a real good head on his shoulders," said Daley.

"He is just a real good kid, he would be worried but in a good way.

"He wouldn't let it get to his head and still has the self belief in his ability.

"It is hard for a young guy. I remember my first Origin game we got smashed 36-6 and I thought `gee I don't belong here' but eventually you get over it.

"My second game was better and third game better again.

"If people around him are playing well then he plays well as well."

Mullen's injury opens the door for Manly halfback Matt Orford and Cronulla's Brett Kimmorley to sneak into the NSW side.

Kimmorley was overlooked in favour of Mullen for the opening Origin clash, but it is believed Orford has shot to contention with his match-winning field goal against Melbourne on Saturday night showing selectors he can perform in clutch situations.

Orford gets a final chance to press for selection against Craig Gower-led Penrith on Friday while Kimmorley has the ideal scenario facing Maroons' half Johnathan Thurston and North Queensland in front of NSW coach Graham Murray on Saturday night.

Brought to you by AAP © 2024 AAP