How long does a head coach have to replace a disqualified player when a substitute is available?

A head coach has 20 seconds to replace a disqualified player when a substitute is available. This rule is in place to ensure the game flows smoothly and that teams are not unduly delayed due to player substitutions. The 20-second limit allows coaches enough time to make strategic decisions regarding player substitutions without significantly interrupting the game. Coaches must act quickly, as failure to do so may result in penalties for the team, including the possibility of the disqualified player remaining on the court if the substitution is not executed in time. Other answer choices suggest longer time frames, which would be impractical for maintaining the pace of the game and ensuring fair competition.