PENRITH, AUSTRALIA - JULY 19: Nathan Cleary of the Panthers (R) celebrates with Mitchell Kenny (L) after scoring a try during the round 18 NRL match between the Penrith Panthers and the St George Illawarra Dragons at Panthers Stadium on July 19, 2019 in Penrith, Australia. (Photo by Matt King/Getty Images)

It has been revealed that the Penrith Panthers are under investigation for having play halted during Saturday night's semi-final victory over the Parramatta Eels.

With the Panthers leading by two points and just minutes on the clock, hooker Mitch Kenny went down with an apparent ankle injury, being twisted awkwardly as he attempted to make a tackle on Parramatta prop Reagan Campbell-Gillard.

While the NRL rules state a trainer must make an initial assessment on the player before play is stopped, that didn't occur on Saturday.

First reported by The Sydney Morning Herald's Michael Chammas on Monday morning, NRL head of football Graham Annesley used his Monday footy briefing to confirm the news.

Trainer Pete Green called for play to be stopped from the sideline, telling the touch judge nearest to his position, with the game paused due to serious injury.

Under the NRL rules, "should an injury necessitate a doctor coming onto the field, the head trainer who carries out the initial assessment is to attract the attention of the nearest touch judge who can electronically communicate with the referee to advise him that the injury is serious. The referee must stop play before a doctor or any other medical assistance can enter the field of play."

The rules also state that penalties may apply to any trainer who stops the game without cause.

"Any trainer who attempts to unnecessarily stop play for tactical reasons will not only be liable to penalty under the provisions of the NRL rules, but may also be ordered from the playing area for the remainder of the match."

"That's underway as we speak. I know there is an intent to get that resolved within the next 24 hours," Annesley said.

SYDNEY, AUSTRALIA - MAY 15: NRL head of elite football operations Graham Annesley speaks during the 2019 State of Origin series launch at Bradfield Park on May 15, 2019 in Sydney, Australia. (Photo by Matt King/Getty Images)

The incident was a topic of hot debate in the immediate aftermath of the contest, with the stoppage stunting Parramatta's momentum as they attempted to find a last-ditch way to keep their season alive.

While the free interchange which was used has been cleared, the on-field stoppage of play hasn't.

It's understood the trainer in question was previously handed a please explain for having time called off following an incident which involved second-rower Viliame Kikau back in Round 14.

If the NRL aren't satisfied Penrith didn't breach the rules, then he could be suspended for the preliminary final this coming Saturday.

Penrith went on to win the game, however, Eels' coach Brad Arthur was displeased to say the least by the way much of the game was handled.

The Panthers 8-6 win will set them up for a shot at a second straight grand final, however, they will have to move past minor premiers the Melbourne Storm at 4pm on Saturday, with the game to be held at Suncorp Stadium in Brisbane.

No team being forced to play in Week 2 of the finals has made the grand final since the North Queensland Cowboys did in 2017, with history stacked against the men from the foot of the mountains.

The other preliminary final will see the South Sydney Rabbitohs play the Manly Sea Eagles on Friday evening, with the grand final to be held the following Sunday, October 3, also in Brisbane.