YORK City Knights were today sweating on the outcome of winger Johnny Waldron's trip to hospital.

The speedy recruit from York Acorn ARLC had to be carried off the field in the second half of last night's friendly against Castleford with what looked to be a serious knee injury.

The Knights lost the game 18-16 to a last-minute converted try, but of more pressing concern was the 24-year-old's well-being.

He was going to have his knee checked out today, with fears he might have popped the kneecap or, more probably, damaged either the ligament or cartilage.

Knights boss Mick Cook said: "It's a blow. He's been playing well and been quite impressive."

Waldron's former Acorn team-mate, Kyle Palmer, also had to come off after his shoulder problem flared up again. It was Palmer's first start for the club.

The rest of the team came through the game unscathed, although Aussie second-row Dave Buckley had to sit it out as he had a cold, with Nathan Priestley, who passed a fitness test on his knee, being a direct replacement. Ryan McDonald also turned out despite cold symptoms.

Cook was disappointed with the result but said he had gained valuable lessons.

"Territorially we had a lot but we didn't get any points from it," he said. "We weren't clinical enough and made too many mistakes. It's a trend we have to break to do well in the competition.

"We had just one attacking kick in the first half, which is pretty ordinary. We did not build any pressure considering we spent so much time in their half.

"Our finishing was poor. We had enough line breaks and territory to win a game. But we're learning from it and we know what we need to do to improve."

Castleford brought an Academy side to Hunting-ton Stadium, barring first-teamer Danny Brough, the former York favourite, but the Knights too fielded a young team, with several first-teamers left out.

Seven of the 19 on show were in the amateur game at the back end of 2006, and half a dozen are of Academy age.

Cook said: "We've got a lot of young players and it's games like these that they need. I need to know that, if we need them, they can do a job.

"We had quite a few players out who you would expect would make a difference to the team."

Cook had particular praise for 18-year-old New Earswick All Blacks ARLC hooker Tom Hodgson, who came on at half-time for his first game for the Knights. Hodgson is unlikely to be considered for a competitive first-team match in the immediate future as it would mean he would be ineligible for the amateur Community Lions' tour to Australia in the early summer. But Cook says he is definitely one for the future.

"I was quite impressed," he said. "He looked sharp and was smart. He made some good decisions and got stuck in defensively. He's going to sign for our Academy and keep his options open regarding the tour to Australia. He looks a good prospect."