Knight made his major league debut with Cincinnati in 1974, but didn't become a regular there until replacing the exiting Pete Rose at third base in 1979 (Rose had signed with the Philadelphia Phillies). Knight was not on the major league roster for the Reds two championship teams in 1975, and 1976. Knight was an All Star in 1980 with Cincinnati, and made the team once again in 1982 while a member of the Astros. In 1984 Knight was traded mid-season to the Mets, where he would wind up on the World Champion Mets team of 1986.