Eddy suffered his only loss. The Chicago White Sox signed him in 1965 as an amateur free agent, though he was expected to attend college for a semester before joining the organization. Professional career Minor leagues (1966–1970) Eddy made his professional debut as a pitcher in 1966 with the Deerfield Beach Sun Sox, which moved to Winter Haven, Florida, during the season. The Sun Sox were a member of the Class A Florida State League. In 16 games, 12 of which were starts, he had a 4–8 record, a 2.07 ERA, 86 strikeouts, 43 walks, and 71 hits allowed in 100 innings pitched. However, Eddy spent the next two seasons in the United States Army. He did not pitch again until late in the 1968 season, when he pitched 15 innings for the Duluth–Superior Dukes of the Class A short season Northern League. In three games (two starts), he had a 1–1 record and a 3.60 ERA. In 1969, Eddy had a historic season for the Appleton Foxes of the Class A Midwest League. Posting an 18–3 record, he led the league in wins, winning percentage (.857), ERA (1.81), placing third in strikeouts (140) and innings pitched (164). His 18 wins and 1.81 ERA were both franchise records. For his efforts, he was declared Appleton's Most Valuable Player (MVP). After the season, he pitched in the Florida Instructional League and also played winter ball in Venezuela with the goal of developing a better slider. After serving mostly as a starting pitcher in 1969, Eddy was used nearly exclusively as a relief pitcher with the Tucson Toros of the Class AAA Pacific Coast League (PCL) in 1970. His teammates jokingly nicknamed him "The Vulture", as he recorded several wins without having to throw as many innings as the starters. In 34 games (one start), he had a 10–4 record, nine saves, a 1.37 ERA, 36 strikeouts, 21 walks, and 41 hits allowed in 59 innings. Chicago White Sox (1970–1971) On September 3, 1970, Eddy joined the White Sox on his first Major League Baseball (MLB) callup. He made his MLB debut on September 7, pitching an inning of scoreless relief in a 7–5 loss to the Oakland Athletics in the second game of a doubleheader at Comiskey Park. In seven games as a rookie, he had no record, a 2.31 ERA, nine strikeouts, six walks, and 10 hits allowed in innings.