adbono,
Got it, that is why I asked.
Catcher would only have a general idea, based on what the pitcher tells him he has, how his warm up pitches go (hopefully showed all his pitches in warm up) and batter setup (unless he has seen the hitter before, like watched his BP or prior inning).
It should be the pitchers decision on what to throw.
So go with these two:
Talk with the pitcher to determine what they have or want to throw. He should run through the signals for the pitches the pitcher has (mixing the sequence each time), until he received the yes head shake. Same as normal pitch shake offs.
Work out a signal, like taping the face mask before the sign to let the pitcher know it is a pitch one of the coaches sitting behind him said he wanted to see. So the pitcher throws that pitch.
Thanks