As long as the coach joins a conference in progress, only one conference (to the coach) would be charged if the pitcher is not removed. NOTE: The initial conference (catcher or other defensive player) is over when the home plate umpire deems it to be completed and asks the defensive player to leave the mound for play to resume. Home plate umpires should be clear in summoning the player away from the mound and should look to the defensive dugout to see if the coach is entering the field.
If the pitcher is removed, no conference is charged. However, if the catcher goes to the mound and the umpire indicates to him that it’s time to start play, then the coach asks for “time” to also confer with the pitcher, 2 defensive conferences could be charged (or 1 for the catcher’s conference if the pitcher is removed).
The practice of sending the catcher out to delay while a relief pitcher warms up quickly before the coach comes out of the dugout risks using additional defensive conferences.