Saturday's Six Nations game between France and Wales in Paris ended with 20 minutes of stoppage time and controversy over the replacement of Les Bleus prop Uini Atonio.
- So what happened?
Uini Atonio was taken off for a head injury assessment (HIA) and replaced by Rabah Slimani, who had been substituted for tactical reasons earlier on in the game. This happened in the 81st minute of a game that eventually ran to 100 minutes.
Wales believed that the HIA process had apparently been used as a method of getting Slimani - a superior scrummager - back on to the pitch, as France looked to exert set-piece dominance in pursuit of a winning try, which duly happened.
Wales' interim head coach Rob Howley claimed that a member of France's coaching team ran outside the designated technical area, which is not allowed, and spoke to Les Bleus' team doctor, who then went on to the pitch and told referee Wayne Barnes that Atonio needed an HIA. Just before that, following the doctor's first pitch arrival, Barnes had asked Atonio if he was injured, and the player replied that he had a sore back but could play on.
- What is a head injury assessment?
A player can be removed for an off-field assessment during a game if signs or symptoms of concussion are unclear, according to World Rugby's HIA procedure.
The assessment won't diagnose concussion but it can identify a suspected concussion, with a player undergoing a series of cognitive, balance and memory tests to determine whether they are fit to continue.
If a player is suspected of concussion after an assessment, they are permanently removed from the match and supported by the HIA.
Regardless of the result, any player who undertakes a HIA must undertake further clinical assessment after the game, and then 36-48 hours later.
- Can a substituted player rejoin the match?
If a player is substituted, as was the case with Slimani, they can only return to the field of play in one of four instances: replacing an injured front-row player, replacing a player with a blood injury, replacing a player undertaking a head injury assessment or replacing a player who has been injured as a result of foul play. A substituted player cannot return for tactical reasons.
- What did Rob Howley say about the change of prop?
"The process leading up to the change of the French tighthead, the way that occurred, we love our game too much to have those decisions. It's hugely disappointing. I just question the integrity of the decision that was made. There is evidence to suggest the integrity of the game has been brought into disrepute."
- What did France boss Guy Noves say about the change of prop?
"I was told that Uini Atonio was injured, so I took my responsibilities and changed the player. The Welsh players also changed players during the stoppages of play. As with all the matches, I have to take stock of the health of the players with my medical staff. I hope this is not too serious and that he (Atonio) will be able to play again very quickly."
- What happens now?
Six Nations Rugby announced on Sunday that it is investigating the circumstances surrounding the head injury assessment during stoppage time. This will inevitably be a detailed probe, and could take some time.
France head coach Guy Noves and his management team are likely to be under the microscope, and it's possible that a misconduct charge could be laid. If that happens and any case is proven, then the French Rugby Federation can expect to face severe sanctions.