Rather than offer a fixed suspension to the St George Illawarra forward, the match review committee referred Couchman directly to a hearing at NRL headquarters, to be held on Tuesday night at 6pm (AEDT).
The league typically takes such action for either the most serious offences, or those where the severity of the tackle is open to debate.
Former Manly prop Tof Sipley was the last men's player referred to the judiciary, eventually receiving a four-game ban for a hip-drop tackle in round seven last year.
Any suspension to Couchman would be a blow to the Dragons' pursuit of a first win this season.
The Red V have winnable clashes against Gold Coast, North Queensland and Manly in the next three weeks and will desperately want the highly-rated forward on deck.
A possible suspension looms as a frustrating setback for Couchman, who was restricted to only one game last season by his own anterior cruciate ligament (ACL) injury.
Couchman went to the sin bin during the first half of Sunday's 30-20 loss to Parramatta for the tackle that is suspected have ruptured Hopgood's right ACL.
After fulltime, Eels coach Jason Ryles said such tackles were inevitable when administrators kept tweaking rules to speed the game up.
"Those tackles, 99.99999 per cent of the time the boys don't mean it. It's not intentional," he said.
"But unfortunately you keep throwing fatigue into the game and you keep making them even more tired, they happen."
Elsewhere, North Queensland centre Tom Chester is set to miss Saturday's match against Melbourne following his high shot on Gold Coast fullback Jayden Campbell.
Chester went to the sin bin for the cover tackle on Campbell late in the Cowboys' 30-16 defeat of the Titans on Sunday.
He will miss an additional match against the Dragons if he unsuccessfully challenges his grade-two careless high tackle charge at the judiciary.
Chester is likely to be replaced by Zac Laybutt in the starting line-up against the Storm in round four.
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