Usman Khawaja scored 75 runs to lead an Australia fightback on the third day of the second test against South Africa at St George's Park, but succumbed just before close of play after seeing the tourists cancel out a first innings deficit.
The ICC announced on Monday morning that Rabada, who rattled through the Australian batting line-up and now has six wickets in their second innings, will have to answer a Level 1 offence for his send-off of controversial opener David Warner on Sunday.
Sunday began with de Villiers making a 22nd test century with his 126 not out taking South Africa to 382 all out for the big lead.
South Africa then started well with the ball.
De Villiers, who had not scored a ton in his last 13 tests, featured in an 84-run partnership with Vernon Philander for the eighth wicket as the pair saw off any potential impact of the new ball from an Australian attack that looked exhausted after their exertions on Saturday. That began with a century by AB de Villiers, constructed on Day 2 and completed early on Sunday, which gave the home team the initial advantage of a 139-run first-innings lead.
Fast bowler Kagiso Rabada, under threat of a suspension which could rule him out of the rest of the four-Test series, made a key breakthrough for South Africa when he bowled David Warner for 13 during a hostile opening spell in which his fastest delivery was timed at 151 kmh.
The left-hander averaged 24.59 outside Australia prior to Sunday's dogged dig, having either been dropped or failed to get a game on the test side's three previous tours. De Villiers suggested that South Africa's best bet might be to surround their bowler in the aftermath of a wicket.
Mitchell Marsh - who put on 87 for the fifth wicket with Khawaja - will resume on day four unbeaten on 39, yet Rabada's late strike leaves Australia facing an uphill battle to avoid a defeat that will level the four-match series.
Whatever the outcome of the hearing, there will be sympathetic support for Rabada - more than players with fewer demerit points to their names might command.
Saker said Australia had not lost hope.
Cricket is a competitive game, and sledging will naturally occur when two sides are going at it, especially when two sides as competitive as Australia and South Africa are involved. "I won't say we're frustrated". I was quite nervous, I haven't been in this position for a while and it means the world to me. There was a lot of emotion from that last Test match (in Durban) going into this one and once again as a fast bowler you want to prove things to people, and you want to show everyone you belong on this stage.
He told batting partner Vernon Philander that he was struggling to breathe and that his legs felt numb.
"I still feel our bowlers have a lot in them and they are going to come with a lot of fire on Monday morning and hopefully knock them over".