How many pitchers are on a major league team?

You still have your 40 man roster that you use for swapping players game to game, however, your actual game roster is still only 25 men. During the playoffs you cannot bring players up from the minor leagues, that is why teams and managers will put guys on the 40-man roster. The entire 40 man roster travels with the team during the playoffs as well, which is why the dugouts are a little more full