The war of words between the Springboks and All Blacks has intensified ahead of their second Test, with South Africa raising concerns over a New Zealand tackling tactic.
The latest issue surrounds the All Blacks’ use of so-called ‘seatbelt’ tackles when attempting to strip the ball from Springbok carriers.
There have been reports that the Springboks have raised concerns about the technique, amid fears it can result in high tackles, head contact and neck rolls.
It adds another layer of intrigue ahead of the latest meeting between rugby’s greatest rivals – particularly after New Zealand made an approach of their own to World Rugby.
New Zealand conceded a number of penalties at the set-piece despite eventually fighting back to claim a 33-16 victory.
Rennie said the All Blacks had brought scrum issues to the attention of the governing body and wanted South Africa forced to scrum square rather than being allowed to step sideways and work around their opponents.
The latest intervention from the Springboks therefore gives the build-up a tit-for-tat feel, with both camps now highlighting areas of the opposition’s game ahead of the rematch.
Springboks flag All Blacks tactic
South Africa's latest concern centres on the way New Zealand defenders attempt to wrap high around the ball carrier and dislodge possession.
It is not the first time the Springbok camp has highlighted concerns over the All Blacks' physical approach during the current series.
Ahead of the opening Test, assistant coach Felix Jones revealed South African franchises had raised concerns about New Zealand's breakdown work, including what he described as tucked-shoulder and non-wrapping actions.
Jones stressed that South Africa had no problem with New Zealand bringing physicality, but wanted that physicality to remain within the laws.
Under Law 9, a player must not tackle an opponent early, late or dangerously, while World Rugby specifically states that dangerous tackling includes contact above the line of the shoulders.
With both camps now highlighting aspects of their opponent's game, there will be plenty of attention on the referee and his officiating team when the rivalry resumes.