NEWCASTLE's star second-rower Steve Simpson says the key for Riley Brown tonight - if he becomes the latest forward to fill the five-eighth spot for the Knights - will be to avoid the temptation to push his luck against Cronulla.

Knights acting chief executive Steve Crowe yesterday confirmed Daniel Abraham, who made his name as a back-rower but who has been playing at five-eighth recently, would not be able to play because of an ankle injury.

"'Abes' is out," Crowe said. "'Riles' is a good chance to play No.6. He's played halfback, five-eighth, hooker, second row and lock in his career, so he's had plenty of practice at switching positions. He'd be up to it, but Brian [Smith, the Newcastle coach] hasn't made a final decision yet. Kurt Gidley is also in the frame."

Newcastle began the season with Jarrod Mullen at five-eighth and Andrew Johns at halfback, but the career-ending neck injury to Johns stretched their resources. Mullen went to halfback when Johns retired, and Abraham to five-eighth.

But now, because of the injury Abraham sustained in last week's 20-16 loss to Brisbane, the Knights have been forced to make another move.

Switching Gidley from fullback to five-eighth would force a reshuffle in the back line, with Todd Polglase having to switch from wing to fullback and another back - probably George Carmont - coming in. Moving Brown from the bench, where he was named, remains the more likely option.

NSW and Australian representative Simpson said Mullen, who is maturing fast despite turning 20 only three weeks ago, would have to accept more responsibility if he was joined in the halves by Brown.

"Abes and 'Mullo' had a good combination going," Simpson said. "They were getting better every week. Abes being out puts a lot more heat on the halves, but Riles is a good young player and I'm sure he and Mullo would do a good job together if that's how we lined up.

"Mullo would do most of the play-calling in that situation, but he's up to that. If Kurt stays at fullback, he can still move up sometimes, as a second receiver, and take some pressure off Mullo. Riles, if he saw something from five-eighth, would be good enough to try to take advantage of it, but the key for him, if he plays there, will be to not over-play things. He would just have to keep things fairly simple.

"It would be up to the rest of us around Riles to keep talking to him and encourage him during the game. He believes in himself, so I think he'd go well."

The Cronulla halves pairing of Adam Dykes and Brett Kimmorley is full of confidence after combined to good effect so far this season.

In recent years, the Sharks lost the vast majority of matches in which Dykes and Kimmorley combined, but, under a different playing style introduced by new coach Ricky Stuart, they are succeeding as a combination.

Cronulla won't be bothered by playing in front of a parochial Newcastle crowd since they have won the past two times they have played there.

The Knights are in the early stages of trying to come to grips with life after Johns. The game against Brisbane was played out in such a way as to suggest that had a player of his calibre been out there, Newcastle would have won. But they can't get Johns back and Simpson says the Knights have to concentrate on minimising errors.

"We've been making too many mistakes and that has hurt our chances of competing in games," Simpson said. "We have to stop that if we hope to start winning consistently."

Newcastle reserve forward Daniel Tolar is unlikely to play, because of a rib problem. Stuart said yesterday there were no injury doubts over his players.