Pitching mostly in relief, the righthander had a ten-year career in the majors. He threw for the Phillies, Cardinals, Giants, Indians, Astros, Padres and Blue Jays where he compiled a career 48-51 record with 41 saves and a 4.31 ERA, along with six complete games.

Acquired by Houston after the 1973 season for reliever Cecil Upshaw, Johnson posted a 2-1 record with a 4.80 ERA in 34 games for the Astros in 1974 before he was released in November.