The Dragons finished the regular season in ninth spot, but could have snuck into the top eight had sixth-placed Manly been sanctioned earlier.

Fairfax Media revealed five months ago that the Silvertails were under scrutiny after Strike Force Nuralda, the taskforce assembled by NSW police to investigate match-fixing, found evidence of player payments in contravention of NRL rules.

Rugby League Central issued breach notices to the Sea Eagles and two current club officials on Monday after identifying potential breaches of the salary cap over the past five years. Potential punishments include large fines and the deregistration of the administrators involved.

The sanctions are cold comfort to the Dragons, who were pipped for a finals spot by a team over the limit.

"It's inappropriate for us to be making comment about a breach notice and an investigation that doesn't involve us and where we are unaware of the facts," St George Illawarra CEO Peter Doust said.

Had the NRL identified the issue during the season, it's likely Manly wouldn't have played for points until such time as the club was cap-compliant.

The situation – faced by Parramatta after their salary cap rorting came to light last year – could have provided the Dragons with an opportunity to contest the finals.

Such an outcome would have generated about $500,000 in additional revenue when finals prizemoney, merchandise sales, corporate interest, membership take-up, sponsor exposure and other incentives are factored in.

A play-off appearance would also have taken the pressure off Paul McGregor. The coach was re-signed after a strong start to the year that saw the Red V lead the competition after seven rounds.

Yet despite having two more years to run on his contract extension, the man dubbed "Mary" will be under huge pressure after missing the finals in successive seasons.

"Obviously to play finals footy would be great for the club for all those reasons, particularly for the supporters," said Dragons legend Mark Coyne, a member of the club's football performance committee.

"But it is what it is and it's not the first time that's happened. I don't think the Dragons should be relying on someone cheating the salary cap to get in there.

"While it would have been good to make the finals, as a player or supporter I wouldn't be saying, 'we've been ripped off because Manly spent a few hundred thousand over the salary cap'.

"We needed to perform better than what we did to make sure we were in the finals for how we played, not because of what's happened with someone else."

Historically, the NRL hasn't compensated teams affected by clubs breaching the salary cap.

When Melbourne was stripped of their 2009 premiership for systemically cheating the system, losing grand-finalists Parramatta weren't crowned premiers.

When the Eels were caught over the limit last year, they were docked 12 competition points and fined $750,000, as well as being stripped of their Nines trophy.