 In October 1976, Rader was traded to the St. Louis Cardinals where he served as a reserve catcher working behind Ted Simmons during the 1977 season.After one year with the Cardinals, he was traded to the Chicago Cubs in December 1977.Rader became the Cubs' regular catcher during the 1978 season, playing in 114 games but, only managed to post a .203 batting average and, in February 1979, he would be traded to the Philadelphia Phillies.