During a rugby match between Australia and South Africa on September 27, Eben Etzebeth, a key player for South Africa, left the field, returned briefly, and then left again. The match ended with a score of 42-38 in favor of Australia. This unusual sequence of events has sparked questions about the rules surrounding player substitutions, especially when an injury is involved. Etzebeth left the field around the 64th minute after a neck collision. He returned approximately three minutes later but left definitively in the final minutes of the game. South Africa used all eight of its available substitutes from the start of the second half. Rassie Erasmus, the Springboks' coach, explained that Etzebeth initially left for a head injury assessment (HIA), a protocol used to evaluate potential head injuries. However, he noted that the player was ultimately recorded as injured, not undergoing an HIA. This distinction is important because the rules treat these two scenarios differently. According to Law 3 of World Rugby, a player who is injured and replaced cannot return to play. For international matches, the match doctor determines whether it is imprudent for the player to continue. If Etzebeth was recorded as injured and replaced definitively, the published rule does not provide for his return. The law also allows for a temporary replacement in cases of injury involving bleeding, and the HIA protocol permits a similar temporary replacement in matches that apply this protocol. In such cases, a player can be temporarily replaced even if all substitutions have been used. The replacement becomes definitive if the player does not return after 12 minutes of real time. A player replaced tactically can also return in certain limited cases, including the replacement of a player with a head injury. In short, a neck collision alone does not open the right to an HIA replacement. It is necessary for the protocol to have actually been triggered and for the return conditions to be met. If Etzebeth's exit was due to a temporary HIA, a return could have been authorized after the assessment. However, the public file does not allow a determination between the two scenarios. A Reddit post published on September 30 by the user MyReddit199 accuses the Springboks of deliberately circumventing the replacement rules. Erasmus's statement confirms a confusion regarding the nature of the exit. It does not demonstrate an intention to deceive. Asserting that a violation occurred or that a penalty was due would require clarification from officials or World Rugby.