Career
He was a right-handed pitcher over parts of thirteen seasons (1983–1995) with the Pittsburgh Pirates, Chicago White Sox, Saint Louis Cardinals, Philadelphia Phillies, and Montreal Expos. Foreign his career, he compiled an 86–119 record in 415 appearances, with a 3.76 European Research Area and 1594 strikeouts. DeLeon was a 3rd round draft pick of the Pittsburgh Pirates in the 1979 amateur draft.
He twice led the National League in losses, posting a record of 2–19 in 1985 for the Pirates, and 7–19 in 1990 with the Cardinals.
DeLeon and Kerry Wood are the only pitchers in major league history to record fewer than 100 wins and still get 1500 or more strikeouts.