Daniel was replaced midway through the first half of Saturday's 24-16 win against the Warriors at Redcliffe and did not return. He was reported to have a suffered a high-grade medial-ligament strain that could sideline him for a month or more.

His setback came 24 hours before the Blues were due to name their team for this year's interstate-series opener at Accor Stadium on Wednesday week.

In his absence, his fellow "Twin Tower" Jacob travelled to Sydney on Sunday to join the extended Blues squad, alongside Newcastle back-rower, 14-game Origin veteran Tyson Frizell.

NSW coach Brad Fittler is an unabashed fan of Daniel Saifiti, who has played in seven Origins and helped the Blues win two series.

A big game against the Warriors might well have sealed a spot in NSW's engine-room rotation for game one in the series.

Instead he lasted only 23 minutes and was replaced soon after hurting himself making a desperate, try-saving tackle on Warriors halfback Shaun Johnson.

"He's in a leg brace at the moment ... I won't know until he has a scan, but for him to come off and not return, it's not good signs for us," Knights coach Adam O'Brien said after Saturday's game.

O'Brien said it was especially disappointing because Saifiti had been showing signs of returning to top form before he was injured.

"He's tried hard over the past few weeks and I just sense that there's a [big] game coming," O'Brien said.

"The thing that I do love about Saf is that he owns his performances. He's not making excuses. He's actually the first one to stick his hand up and critique his form.

"But I'm seeing signs there where he's trying really hard to get a game, and for that to happen, it's disappointing."

If Jacob gets to play for NSW, he and Daniel will become the first twins since Josh and Brett Morris to represent the Blues. Kerrod and Kevin Walters played for Queensland more than 20 years ago.

Frizell, who missed last year's series through injury, clinched a recall by scoring a try, gaining 125 metres and making 42 tackles in a tireless 80-minute display against the Warriors.

Jacob came off the bench when Daniel was injured and played 51 minutes, making 104 metres and 27 tackles.

There was no place in the NSW squad for arguably Newcastle's bext player this season, David Klemmer, who spent 76 minutes on the field against the Warriors, making 42 tackles and 138 metres.

Newcastle will not be happy with a scrappy performance against the Warriors, marred by nine handling errors and 21 missed tackles, but were relieved to have posted their fourth win of the season, climbing from 15th to 13th on the ladder.

"It's sort of a new season for us, starting now," O'Brien said. "I know we'll have a few boys who have a job to go and do for their states, but the back end of the year is a bit of a re-set ... we come back in a fortnight's time against a pretty handy outfit in the Panthers, but I still believe this team will do something.

"We can fight our way into finals. We've done it before and we can do it again."

The Knights produced an awful start, conceding soft tries to centres Adam Pompey and Viliami Vailea to trail 10-0 after only nine minutes.

The recovered to level the score at 12-all shortly before half-time, then clinched a hard-fought victory with two Enari Tuala tries in the second half.