The incident took place during Penrith Panthers' thrilling 30-26 extra time win over Gold Coast Titans at the weekend, when Jayden Campbell was taking a potential match-winning conversion kick late in the match.
Trainer Corey Bocking was seen to have run in front of Campbell during the kick in what Penrith insisted was an accident with no ill-intent.
Campbell had to withdraw from and recommence his kicking routine before missing the conversion attempt.
"The NRL has issued Penrith Panthers with a breach notice relating to the actions of a Club trainer in Round 22," the league said in a media release on Monday afternoon.
"The breach notice proposes a fine of $50,000 for the Club, as well as a five-match suspension for the trainer involved.
"It is alleged the trainer unnecessarily interfered with and distracted Gold Coast Titans player Jayden Campbell as he was attempting a conversion kick, in breach of the NRL Operations Manual and NRL Code of Conduct.
"The proposed penalty takes into account previous breaches by Penrith Panthers trainers."
The previous breaches referred to by the NRL includes Bocking's colleague Shane Elford, who was sanctioned for squirting water on a ball earlier this year.
"Did it cost us the game? I don't know," said Titans coach Des Hasler of the incident.
Penrith have been given five days to submit an appeal.