He also pitched in the inaugural National League Division Series in 1981 with Philadelphia (vs. Montreal); the Division Series format was adopted as a result of the players' strike. Reed's finest season in Philadelphia was his last. In , Reed pitched 95.2 innings, and went 9–1 with eight saves. He appeared in three of the five World Series games against the Baltimore Orioles. After the season, and shortly after his 41st birthday, Reed was traded to the Chicago White Sox for a player to be named later. The Chisox sent fellow 41-year-old Jerry Koosman to the Phillies to complete the trade.