Dennis Patrick Leonard (born May 8, 1951) was one of the Kansas City Royals' most dominating pitchers of the late '70s and early '80s, but his career was cut short due to injuries.
Born in Brooklyn, Leonard attended Oceanside High School on Long Island, then played college baseball for and graduated from Iona College. In 1975, his first full year with the Royals, he managed to bust out with a 15-7 record. He would keep adding onto that with three 20 win seasons, but more impressive was the amount of games he started and finished. Despite his success in the regular season his post season record is less than impressive. He started 9 postseason games for the Royals between 1976 and 1981, but ended with a record of only 3-5, including a 1-1 record in the 1980 World Series against the Philadelphia Phillies.
Towards the end of his career he missed most of the remaining seasons due to knee injuries. His final season was in 1986 where he ended up with an 8-13 record despite a strong showing. Besides his rookie season of 1974 this was the only time he had a losing record. At the end of the 1986 season he retired as a player.