Castleford Tigers boss Lee Radford on Danny Richardson ACL fears and Liam Watts concern

Richardson, who was Castleford's only fit and available half-back on Monday, was helped from the field in the closing stages of the first half to leave Radford fearing the worst.

Although the Tigers have yet to determine the full extent of Richardson's knee issue ahead of a scan tomorrow, Radford is resigned to being without the playmaker for a chunk of next season.

"The physio (Matt Crowther) has been right with most assessments he's done because he's had a few," said Radford, who has lost Jake Trueman and Ryan Hampshire to similar injuries in recent months.

"Matty has never seen a season with three blowouts. It's a fair old amount in one season, especially with the importance of the positions of the players.

"The players haven't downed tools; they've continued to crack on and have a go.

"Round one was the only week we had our spine available to us and every other week has been a patch-up job.

"That's a real frustration and I'm hoping moving forward we're going to be so much better for having the players in those important positions available more often."

Radford will once again be without Gareth O'Brien when Castleford visit Headingley on Saturday, meaning the Tigers go into the do-or-die clash with play-off rivals Leeds Rhinos without a specialist half-back.

Liam Watts drops out of the team comprehensively beaten by Salford after picking up a sixth suspension of the season for a late hit.

Radford has admitted the prop's disciplinary issues amid a clampdown on foul play have become a major problem.

"You've got to accept that there are changes first and then you can adapt to that," he said on the 32-year-old.

"If you asked Liam, he is struggling a bit with it. The game has changed and what you could do three or four years ago, you can't do anymore.

"Either you adapt or you fall by the wayside. That's going to be a challenge for Liam.

"It makes him a squad player being unavailable that much. He's not a squad player and shouldn't be a squad player.

"It's a frustration, definitely. We spoke about it (late hits) after his last suspension and really worked on it during his suspension. That's the frustration with this one.

"The ruling of the game has changed and you've got to adapt - but you've got to want to change."