World Rugby confirmed on Sunday night that the England tighthead had been summoned to an independent disciplinary hearing on Tuesday for an incident that took place in the 64th minute of the Springboks’ 27-9 victory at Cape Town Stadium that levelled the three-match series at 1-1 with a winner-takes-all decider to come next weekend.
Sinckler - introduced from the bench in the second half on Saturday - could face a lengthy ban starting at 12 weeks if the citing is upheld.
The Bristol front row was the only player from either team to be cited by Australian Scott Nowland following Saturday’s ill-tempered Second Test that saw emotions boil over on several occasions, particularly during an ugly, stop-start first half that took more than an hour to complete.
Earlier on Sunday, Lions full-back and Scotland captain Stuart Hogg strongly refuted accusations of biting that surfaced on social media following his clash with opposite number Willie le Roux during one of those first-half flashpoints in Cape Town.
“Following speculation that has surfaced online, I would like to categorically deny any foul play in last night’s game,” Hogg said in a statement.
“I would never bite an opponent and I am annoyed and upset by this unsubstantiated accusation. I’ve always been proud of playing rugby in the spirit of the game.
“Respect to the Springboks for their deserved win yesterday. The squad is hurting after last night’s defeat, but it’s all to play for next week. It’s going to be a cup final and everyone’s going to be up for it.”