Wait.
Are you trying to make the argument that it isn't the responsibility of the team manager to notice that his pitcher is acting like he is hurt with every pitch and actually go out and do something because of it? Even if it is just to go out and talk to him, testing him, make him throw a few warm ups etc., just to check on him?
WHO comes in after that is secondary to the health of the guy on the mound. If by subsequent investigation, you find your guy is hurting, then you go to whoever your next best guys is in that situation.