The captain's challenge is in danger of being hijacked by coaches with several clubs already plotting ways to send rapid-fire messages on to the field to assist their team.

Unlike the rules applied to both cricket and tennis with their video review systems, the NRL will not place restrictions against the captain looking to the bench and coaches box for instruction.

Roosters coach Trent Robinson and Raiders coach Ricky Stuart chat after last year's grand final. Credit:Getty Images

The Sydney Morning Herald on Wednesday approached five NRL coaches, who all believe - as one coach said - "there is more than enough time" for a team's analyst to watch the replay and relay the decision to the players.

The team analyst, who generally sits in the box watching the match and cutting up clips in real time on an editing program, also has access to instant rewind.