If Fuimaono unsuccessfully challenges the grade-three dangerous contact charge, forgoing the 25 per cent early guilty plea discount, he will miss seven games with loading and carryover points applied.
The Eels confirmed on Monday that Dunster, who was a strong chance for a wing spot in round one, had suffered ACL, MCL and PCL ruptures in the 13th-minute incident during Sunday's 26-22 trial loss at CommBank Stadium.
Dunster writhed in pain after the awkward tackle by Fuimaono, who was sent to the sin bin.
Unless exonerated, Fuimaono won't be available for Saturday's Charity Shield clash with South Sydney as players who incur grade-three charges are ineligible for trials.
The 25-year-old's rap sheet includes two previous hip-drop offences in the past two seasons and a reckless high tackle charge for a shot on Melbourne's Ryan Papenhuyzen last season.
Fuimaono was sent off and served five matches on the sidelines for the Papenhuyzen incident in Magic Round, as the NRL put its focus on deterring high contact.
Dunster will have surgery in the coming days.
Parramatta said in a statement they are "fully supporting Haze in his efforts to returning to the field in 2023".
The NRL is set to announce a full list of charges from the weekend's trials later on Monday.
Cronulla pivot Braydon Trindall could be in strife for a high shot on Penrith winger Thomas Jenkins while Dragons flanker Tautau Moga and Eels forward Ryan Matterson were sent to the sin bin for dangerous contact.
