Manly has been slapped with a $10,000 fine for coach Geoff Toovey's post-match blow-up on Friday night, which the NRL deemed excessive criticism of referees.
Toovey unleashed an almighty spray towards the game's officials at the media conference after the Sea Eagles were overrun by South Sydney in going down 22-10 in Gosford.
No official was spared as Toovey questioned a no-try ruling against Steve Matai, the penalty count against his side, as well as separate acts of foul play involving Souths pair Jeff Lima and Greg Inglis.
The five-figure fine handed down yesterday comes in the form of a breach notice, which the Sea Eagles have five days to appeal.
NRL head of football Todd Greenberg said Toovey crossed the line with his emotional reaction.
"I accept that emotion is a big part of our game, but that is not an excuse for making unwarranted attacks on match officials," Greenberg said.
"There needs to be a balance between coaches expressing their opinions and their emotions and showing respect for the game and the match officials in that process."
Under NRL rules, excessive criticism is when someone moves beyond identifying perceived errors and attacks match officials.
During his outburst, Toovey questioned whether the two whistleblowers appointed to the glamour match were the best the league had.