protocol during pitching change

[Andy]

I think that you will find that this particular protocol will vary by region or even by individual. I don't believe that it is a documented practice in any umpire manual that I have seen.

I will usually follow the protocol that you describe, John, for this reason.

If this is a mid-inning pitching change, the PU is probably busy verifying the substitution with the defensive coach, or if it is just a position switch (ie F5 will pitch and F1 will play third), noting the line up card of the new pitcher in case the team wants to use a courtesy runner.

The BU doesn't have anything else to do, so s/he may as well count the warmup pitches and let the new pitcher know the game situation, especially if she is just coming in the game from the bullpen. Of course she can see who the runners on base are, but what does it hurt to say....2-2 count on the batter, 1 out, runners at first and second?