There are no additional citings following a full review of the bad-tempered match in Cape Town. Stuart Hogg the Lions full-back, was accused in the South African press of biting opposite number Willie le Roux in the 27-9 defeat, prompting the Scotland captain to issue a strong denial.
There were several flashpoints in the match but only Sinckler has been summoned to appear. World Rugby, the game’s governing body, described the incident as “an act of foul play contrary to Law 9.12 (biting) during the 64th minute of the second test against South Africa”.
The disciplinary hearing will take place on Wednesday via video conference before an independent judicial committee chaired by Australian senior counsel Adam Casselden and including former Wallaby internationals David Croft and John Langford.
Biting is treated severely by rugby’s judiciary and carries a low-end punishment of a 12-week ban, rising to in excess of 24 weeks for serious offences. The maximum length of suspension is 208 weeks.
Hogg was furious at being accused of biting le Roux as tempers flared in the second half of a fractious second Test which saw the Springboks level the series with one match to play. Inconclusive footage and stills were circulated on social media, but the Scotland skipper rejected claims that he bit his opposite number.
“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 released by the Lions on Sunday. “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. 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.”
Sinckler, meanwhile, now faces an anxious wait. The England prop, who was a second-half replacement for Tadhg Furlong, can expect little mitigation if the biting incident is proven because of his previous misdemeanours.
In January he was suspended for two weeks for swearing at a referee and four years ago he received a seven-week ban for gouging.
A bad-tempered collision turned into a savage grudge match and it is surprising more players were not cited, the requirement for which is that an offence is worthy of a red card.
A clip of Maro Itoje resting his knee on the throat area of Damian de Allende has also been widely viewed on social media.
As Itoje rises to his feet, the protesting de Allende tackles him to floor with the ball long gone and then shouts downwards at the prone Lions second-row.
South Africa made their own contribution to a stormy evening.
Cheslin Kolbe was fortunate to be punished with only a yellow card for taking out Conor Murray in the air and the Springbok wing also clattered into Tom Curry with a clumsy head-first tackle that the officials dismissed.
Duhan van der Merwe, the Lions wing, was earlier shown a yellow card for tripping Kolbe.
Referee Ben O’Keeffe also brushed over another potentially dangerous challenge by Faf de Klerk, who connected high with the unfortunate Murray.
Putting to one side the disciplinary fallout from the penultimate match of the tour, coach Warren Gatland must pick his Lions up from their heaviest defeat since the disastrous 2005 visit to New Zealand.
The Lions toiled up front and their back three were vulnerable to the aerial bombardment they knew was coming, so changes appear inevitable.
“We’ll spend the next couple of days reviewing the game and then looking at what we think is the best 23 to put out,” Gatland said.
“Whether that’s some fresh faces who haven’t been involved in the first two games…we have got lots of options to give us energy and perhaps some momentum as well.
“Or do we put out that same team and give them the chance to redeem themselves? Those are the conversations we’ll have over the next couple of days.”