Parsons was drafted in the 7th round by the Seattle Pilots in 1968,[2] and played in their minor league system.

[citation needed] He joined the Milwaukee Brewers in 1970, and was assigned to Portland of the Pacific Coast League, going 3–0 with a 2.25 ERA.

[1] He was in the starting rotation for the last-place Brewers in his rookie season, going 13–17 with a 3.20 ERA, while 7th in the league with 4 shutouts and 8th in the AL with 93 walks.

[citation needed] He was traded to the Oakland Athletics with cash for Deron Johnson in 1974.

His contract was purchased by the St. Louis Cardinals from the Athletics at the Winter Meetings on December 2, 1974.