Vunivalu was on Monday charged with a grade-two offence for a leg pull on Canterbury fullback Nick Meaney early in Sunday's narrow win over the Bulldogs.
Meaney got up gingerly but the incident was not penalised by on-field officials, before Vunivalu was picked up by the match review committee.
The Fijian will miss just one match if he pleads guilty to the charge.
But if he contests the charge at the judiciary, he would risk sitting out the Storm's grand final rematch against the Sydney Roosters in round six.