EurosportWatmough was handed a grade two unnecessary arm pressure/dangerous contact charge for his 39th minute tackle on Warriors fullback Kevin Locke on Saturday night.
The 28-year-old will have until midday on Tuesday to fight the charge at the judiciary on Wednesday night - where he would face a two-match ban if he fights and loses.
An early guilty plea would rule him out for just this weekend's important clash with North Queensland.
Melbourne halfback Cooper Cronk escaped punishment for his tackle that left St George Illawarra's Ben Creagh in some distress on Friday night.
