NRL superstar Kalyn Ponga's awkward slip of the tongue as Knights captain reveals how he managed to defy injury and return the field against Roosters

NRL superstar Kalyn Ponga left footy fans in stitches following an awkward slip of the tongue moments after Newcastle's 22-20 defeat on Thursday night.

Speaking on live TV post game to Channel Nine's Danika Mason, the Knights skipper spoke about playing through the pain after suffering a hip injury.

'Were you thinking you might have to come off.... or were you determined to stay on?' Mason asked.

'I was never going to pull myself off,' he replied, matter of factly.

Ponga quickly realised his potential X-rated choice of words, and hilariously added 'that sounds a bit weird' before smiling on camera.

Mason somehow kept her composure as the pair enjoyed a laugh together at the faux pas.

Meanwhile, Ponga's coach Adam O'Brien was seething after his team was denied a penalty goal at the death - which if converted, would have sent the contest into golden point extra time.

Trailing 22-20, Ponga tore down the right side but was stopped by his opposite in Joey Manu, with Fetailaga Pauga then holding the fullback as he attempted to play the ball at speed.

The incident slowed the ruck down enough for the Roosters defence to scamper back onside - but it was not deemed a professional foul.

'I empathise. These fans, they know footy,' O'Brien said.

'I don't think I've ever heard a stadium so frustrated, never heard booing like that at the end of a game. There must be something in it.'

O'Brien felt the officiating followed a 'theme' and was similarly displeased with the decision not to award Knights centre Dane Gagai a try due to an apparent obstruction in the second half.

Decoy runner Dylan Lucas took Roosters five-eighth Luke Keary out of the play but O'Brien felt the visitors still had an opportunity to tackle Gagai.

'It's a two v two, it's a missed tackle on the outside. Again, that's another one [contentious call],' he said.

'I'm not taking anything away from the Roosters, but it just felt like we didn't get many rewards.'