The Storm kept their two star players on the field without a head injury assessment (HIA) despite them both appearing to be concussed.

NRL boss Andrew Abdo told the Sydney Morning Herald that the competition's chief medical officer would examine the decisions.

"Our CMO will check all the angles and footage and see if there were any markers requiring a mandatory HIA," Abdo said.

Munster temporarily left the field but then returned, which left Roosters coach Trent Robinson questioning whether the incident in which he was hurt deserved his lock Victor Radley to be sin-binned.

Radley was charged with a grade two careless high tackle by the match review panel for his shot on Munster.

"He (Radley) got 10 in the bin, because, was he (Munster) knocked out? And then he comes back on 30 seconds later," Robinson said after the match.

"So we get 10 in the bin ... so should it be 10 in the bin? That's up to the refs to explain that."

Try-scoring hooker Grant also remained on the field without a HIA despite a head clash in the second half.

Meanwhile, Canterbury plan to appeal the severity of a $20,000 fine for failing to immediately remove Lachlan Lewis from the field after he had suffered a heavy head knock.

The Bulldogs were the first club to be handed a breach notice by the NRL after Lewis stayed on the field for two minutes following an incident during their round four loss to South Sydney.

According to The Daily Telegraph, Bulldogs CEO Aaron Warburton admitted Lewis should have left the field immediately but felt there were mitigating circumstances.

"We completely understand the game can't come down lightly on this issue but, I would like to think, by accessing this breach on its merits, there was a reason why it wasn't quicker than two minutes," Warburton told the newspaper.

Australian Associated Press