Saying "Play"

[njdevs00cup]

When do you verbalize the word "play?"

At the start of the game only? Every time you put the ball back in play? When you put the ball back in play and runners are on base?

I was watching the prior game finish up. The plate umpire verbalized "play!" after a foul ball. The batter stepped out and was punched out on the subsequent pitch. I watched the batter put his hands up and the coach confront the umpire. I've worked the plate umpire several times and he told me the batter thought PU said "wait" and not "play!"