Knights fullback Kalyn Ponga doesn't believe he has a case to answer for an incident that saw Michael Chee Kam stretchered from the field before full-time.

Ponga was sin-binned late in the 28-26 loss to Wests Tigers on Friday night for an alleged act of foul play where his shoulder came in contact with Chee Kam's head as the back-rower was chasing a ball in-goal.

Chee Kam was taken to John Hunter Hospital following the game for tests on his head and neck as a precaution. 

"Obviously my shoulder hit his head and that's no good, I was very concerned for him," Ponga told NRL.com after the game.

"I was bracing for impact, it sucks it his head. I saw the way he was after it and it was pretty scary.

"I don't think anyone would've deliberately gone in to hit someone in the head.

"It sucks and I hope he is OK."

Ponga has a relatively clean judiciary record but could come under scrutiny for the tackle from the match review committee.

He was charged in round eight for tripping but received a fine with no carry-over points recorded.

Knights coach Nathan Brown described the on-field decision as "stiff" following the loss.

"Kalyn's got to make a play, he can't just stand there," Brown said.

"It's just unfortunate. I don't think there's a cleaner player playing the game. I don't think he tried to make a shoulder charge. He was trying to attack the ball."

Neither Ponga or Brown thought the moment cost the Knights the game after they trailed by two points with nine minutes to go.

"I don't feel like I let the boys down," Ponga said.

"I got sent off with two minutes to go but to leak 28 points isn't good enough. We put pressure on ourselves to score so it was a poor effort.

"It's just annoying, we always say we need to have a look at ourselves and decide if we want to compete."

Wests Tigers coach Michael Maguire said he thought Ponga's actions were accidental in his post-match press conference.

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