Bullpen Warm-Up Rule
A. No more than two pitchers may warm up at one time.
B. Relief pitchers must be warmed up for two batters before he is at full
strength. Pitchers are not at full strength until they have warmed up for
or faced two batters. Pitchers are fatigued if they are brought into the
game early.
C. Pitchers who are warming up for the defensive team sits at the end of a
half-inning.
D. Pitchers who are warming up for the offensive team continue at the end
of a half-inning.
E. The time between half-innings counts as one batter faced.
F. Warm up rules do not apply when a pitcher is injured on the mound.
G. Pitchers who warm up four or more times in a game will be fatigued when
entering the game. Warming up four or more times also counts as a day of
use. If the pitcher is used the next day, he must rest at least one day.
See Rule 27.64