A Bullpen catcher is a member of a team's personnel whose main duty is to serve as a catcher when relief pitchers are warming up in the bullpen prior to entering a game. They will also sometimes serve as the catcher for the active pitcher between innings, when the regular catcher is still putting on his equipment as a result of having come to bat, or been on base or been in the on-deck circle when the previous half-inning ended. Bullpen catchers usually wear a uniform with a number but are not considered coaches.
Specialized bullpen catchers began appearing in the 1980s, when most teams stopped including a third catcher on their rosters. It was usually that player's duty to warm up relievers, as he would not often be used in a game, and if a second catcher was needed (for example, when a team is warming up both a righthander and a lefthander), the bullpen coach would often join in. With budgets on the rise in the major leagues, most teams eventually found it advantageous to hire persons specifically to perform these duties. Major league teams now all have either one or two bullpen catchers as part of their staff.
The ranks of bullpen catchers are usually made up of former minor league (or major league) catchers, although teams can also sometimes hire persons whose catching experience has been in college or in the amateur ranks. Many are also hired for their language skills, often serving as interpreters for Spanish-speaking pitchers. Some bullpen catchers eventually graduate to full coaching positions.
- List of current Major League Baseball coaching staffs includes a column listing the bullpen catcher(s) for each major league team.