Three NRL clubs are facing fines totalling $350,000 after being issued with Breach Notices relating to head injuries in Round 3 of the Telstra Premiership.

CEO Todd Greenberg said there is no more important issue in the game than player safety and he was satisfied that the three clubs had failed to follow the concussion rules during weekend matches.

The Breach Notices have been issued to:

• The Gold Coast Titans ($150,000) for incidents involving Kane Elgey, Joe Greenwood and Ryan Simpkins

• St George Illawarra Dragons ($100,000) for an incident involving Josh Dugan

• Newcastle Knights ($100,000) for an incident involving Brendan Elliot

"These are, by far, the heaviest fines ever proposed by the game for concussion breaches," Mr Greenberg said.

"That is how seriously we take it.

"The clubs involved have the opportunity to respond to the Breach Notices, and we will consider those responses, but our message is clear… we are not going to allow player safety to be put at risk through breaches of the concussion rules."

Mr Greenberg said the NRL has put significant resources into concussion training and education.

"In the majority of cases we see strong compliance with the League's concussion rules but it appears that this did not happen at the weekend in some matches and we cannot stand by and allow player safety to be put at risk," he said.

"Where we believe the rules have been breached we will take action – and we would hope that these Breach Notices will serve as a warning to all clubs."

Mr Greenberg said the clubs would have five business days to respond to the Breach Notices.