Two rules here. P has to face 3 batters
Teams limited to 4 mound visits.
Let’s say youre out of mound visits.
Your pitcher has faced one batter in the 9th and other team pinch hits a lefty for your rh pitcher.
You go to the mound w a lefty warming up in the pen.
what now? You’re not allowed the visit without taking him out. He’s only faced one batter. And with a lefty in the pen you clearly wanted this. What does the umpire do?
Manager ejection is my guess. Pitcher stays in to fulfill the three batter rule. Do you know the answer? Interesting quirk or contradiction you noticed.