0
From BR Bullpen
Uniform number 0 was not traditionally worn in baseball, as in most other North American professional sports, until the 1970s. It was the same for number 00. These numbers were traditionally reserved for mascots, bat boys, and for model uniforms. 0 has been worn by a few players on the field, most notably Al Oliver who sported it for various teams in the second half of his career. It has once again become discarded in the 21st century.
