5.07 (b) (8.03) Warm-Up Pitches
When a pitcher takes his position at the beginning of each inning, or when he relieves another pitcher, he shall be permitted to pitch not to exceed eight preparatory pitches to his catcher during which play shall be suspended. A league by its own action may limit the number of preparatory pitches to less than eight preparatory pitches. Such preparatory pitches shall not consume more than one minute of time. If a sudden emergency causes a pitcher to be summoned into the game without any opportunity to warm up, the umpire-in-chief shall allow him as many pitches as the umpire deems necessary.