In the situation where an athlete is struck in the head and the coach requests a preliminary symptom check for concussion, a one-minute technical time out would be applied by the referee to rectify the situation before a legal substitution, exceptional substitution or recovery time would become necessary.
The players are to remain on the court while the situation is being rectified. The technical time-out is not charged to either team. The technical time-out may occur only once for the same player in the match and is recorded on the scoresheet under remarks.
If it is determined that the athlete should be removed for a complete concussion assessment, the athlete may not return to competition until the results of the assessment are known.
32.1.1 Legal Substitution
If possible, a legal substitution would be used. The athlete undergoing concussion assessment may return to the set if deemed clear to continue, providing the return is legal. (Rule 15.6)
32.1.2 Exceptional Substitution
If a legal substitution is not possible then the referee would authorize an exceptional substitution. The athlete undergoing concussion assessment cannot return to play for the remainder of that set. The athlete undergoing concussion assessment may play in subsequent sets providing the results of test deem them clear to continue. (Rule 15.7)
32.1.3 Recovery Time
if an athlete requiring concussion assessment cannot be substituted legally or exceptionally, this player is given a three-minute recovery time. This may occur only once for the same player in the match. If the player is not able to return at the end of the recovery time, the team is declared incomplete. (Rule 17.1)