The governing body has come under fire following a time-keeping blunder in Saturday's fixture between Manly and Melbourne which allowed two Sea Eagles players to return early from the sin bin.

The incident has forced the NRL to review the sin-binning process.

"We own it. We made an error and it won't happen again. I've been pretty disappointed with some of the things I've seen and read over the weekend, (and) that was one of them," Greenberg said.

"There's been a strong directive to our staff today to ensure that doesn't happen again."

He said the competition committee had begun to look at the merits of using the shot clock - which is already being used for scrums and line dropouts - for players sent to the sin bin.

"We've been looking at some technology advancements around sin bins for a few months now," he said.

"Clearly there are some opportunities for us to use some of the shot clocks we currently use as well as the bunker. The short answer is yes, we'll look at it."

His comments come after a single-round record 15 sin bins in the NRL era, with at least one player marched in every match of round 11.

A total 49 players have been sent to the sin bin over the opening 11 rounds in 2018 - the most since 53 in 2000 - however Greenberg vowed match officials would continue to crack down on penalties.

"This time last year I heard calls from players, coaches, fans and commentators about putting more people in the sin bin for repeated offences, and that's exactly what we're doing," he said.

"And we're going to keep doing it until such time as the players continue to follow the rules."

Greenberg also urged referees to crack down on the growing trend of players milking penalties by throwing the ball into ruck defenders, and told coaches to instruct sin-binned players to quickly exit the field.

Australian Associated Press