Greenberg, while supporting the bunker and the manner in which it had sped up the game, said the NRL was examining whether freeze-frame should be allowed to be used when ruling on incidents such as double movements.
"There's a real challenge. Our forefathers who wrote the rule book back in 1908 almost certainly never considered freeze-frame technology," Greenberg told Triple M on Saturday.
"There's no doubt our sport and other sports are having a real challenge in how we implement best practice technology into the modern-day game while using a rule book that was written without the concept of technology.
"What that means in a roundabout sort of way is that - should we adjudicate on all the issues that we're adjudicating on in the game? Or are things like double movements and other things not the right things to look at because it's so hard to interpret a rule book with the use of technology?"
Greenberg said he was also looking at introducing the captain's challenge that had been used in the under-20s competition since 2012.
Allowing players to challenge contentious decisions has been used in cricket and tennis and Greenberg has flagged it as a possible way to quell unrest over video review decisions.
"Whether you put the onus back onto the players, that's a decision that we're going to look at over the course of the off-season and making sure that you take some of that controversy away," Greenberg said.
"The one thing that the technology has provided, and will continue to provide in all sports, is to take away the howler, to take away the one that is missed that everybody gets upset about.
"No doubt it does that but then you've got to be careful you're not micro-managing the game."
- AAP