Ballard was hurt but not concussed in the final-quarter incident at Heritage Bank Stadium on Saturday night.
Van Rooyen appeared to make a genuine attempt at spoiling the ball in the marking contest.
But he caught Ballard high and his action was still considered careless conduct and high impact by AFL match review officer Michael Christian.
The grading resulted in a two-match ban that cannot be reduced with an early guilty plea.
If he doesn't mount a successful challenge, van Rooyen's suspension would cost him the spot in the team he has held since his impressive debut in round three.
The 20-year-old - a first-round draft pick last year - has kicked 11 goals in six senior matches.
Geelong's Brad Close and Hawthorn's Tyler Brockman are both facing one-match bans for rough conduct.
The pair were cited over dangerous tackles on Adelaide's Jordan Dawson and Fremantle's Brandon Walker respectively.
Both incidents were assessed as careless conduct, medium impact and high contact.
Adelaide's Rory Laird can accept a $2000 fine for rough conduct on Geelong's Tanner Bruhn.
Port Adelaide forward Junior Rioli faces a nervous wait for Sunday's match review findings after his high contact with Jordan Ridley behind play led to the Essendon defender being substituted out of Sunday's Adelaide Oval contest.
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