A "cup of coffee" is a North American sports idiom for a short time spent by a minor league player at the major league level. The idea behind the term is that the player was only in the big leagues long enough to have a cup of coffee before being returned to the minors. The term originated in baseball and is extensively used in ice hockey, both of whose professional leagues (MLB and the NHL) utilize extensive farm systems; it is rarely used in basketball or American football since neither the NBA nor NFL have implemented a true farm system.
One example of how this term is used in a sentence was during the 1996 film The Fan, in which Robert De Niro's character, a middle-aged former pitcher, says, "I was in the bigs for a cup of coffee myself until my arm went south."
One well-known variant of the cup of coffee is the September call-up, in which major-league clubs call up additional players to the big leagues from the minors on September 1, when rosters expand from 25 players to 40. This is by definition a cup of coffee, because September is the last month of the baseball season. Notable players who made their debuts in September include Baseball Hall of Fame players Mike Piazza (21 games in September 1992) and Ryne Sandberg (13 games with the 1981 Philles).
Francisco Rodríguez made his big-league debut by pitching 5 2⁄3 innings in September for the Anaheim Angels. Included on the Angels' postseason roster as a replacement for an injured player, he won five playoff games for Anaheim and helped them to a victory in the 2002 World Series, all before he won a regular-season game in the majors.