Hoeft was signed by the Detroit Tigers as an amateur free agent in 1950. He made his major league debut on April 18, 1952 for the Tigers, and went on to pitch seven full seasons in Detroit. On September 7, 1953, Hoeft struck out three batters on nine pitches in the seventh inning of a 6–2 win over the Chicago White Sox. Hoeft became the fourth American League pitcher and the ninth pitcher in Major League history, as well as the first since 1928, to thrown an immaculate inning. On June 24, 1955, Hoeft surrendered the first home run in the career of Harmon Killebrew, who would eventually hit 573 home runs in his career. He was chosen to be part of the American League All-Star squad in 1955. He was primarily used as a starting pitcher in Detroit, starting in 176 games during his time there. His best season came in 1956 when he won 20 games and pitched 18 complete games. He also showed occasional potential as a power hitter, once tying an American League record for consecutive home runs by a pitcher with two to begin a game.
In May 1959, Hoeft was dealt to the Boston Red Sox for Dave Sisler and Ted Lepcio. He was the losing pitcher in three of his five appearances for Boston and was dealt to Baltimore for Jack Harshman after a little more than a month. Hoeft remained in Baltimore through the 1962 season, where he was primarily used as a relief pitcher, although he did start 16 games for the Orioles. During the 1961 season, Hoeft posted a career-best Earned Run Average of 2.02 in 12 starts and 23 relief appearances.
San Francisco, Milwaukee and Chicago (1963–1966)
After the 1962 season, Baltimore traded Hoeft, as well as Jimmie Coker and Jack Fisher to the San Francisco Giants for Stu Miller, Mike McCormick and John Orsino. In 23 appearances for San Francisco during the 1963 season, Hoeft saved four games and posted an earned run average of 4.44. After the season ended, he was dealt to the Milwaukee Braves, along with Felipe Alou, Ed Bailey and a player to be named later for Del Crandall, Bob Shaw and Bob Hendley. San Francisco ended up sending Ernie Bowman to Milwaukee to complete the deal. In Milwaukee, Hoeft put up slightly better numbers than he did in San Francisco, appearing in 42 games and posting an ERA of 3.80. He saved four games for the Braves in the 1964 season. After the 1964 season, Hoeft entered free agency, and was re-signed by his original team, the Detroit Tigers. He was released during spring training for the 1965 season. Shortly afterward, the Chicago Cubs signed Hoeft to a contract for the 1965 season, where he posted an ERA of 2.81 in two starts and 29 appearances for the Cubs. Hoeft's last season in Major League Baseball was 1966, as he appeared in 36 games for the Cubs, before being released in August. In August, he was signed by the San Francisco Giants initially as a coach and batting practice pitcher before being activated in September when playing rosters increased to 40 men. He posted a 0–2 win-loss record in four games pitched during his second tour with the Giants, before announcing his retirement at the end of the 1966 season. Hoeft was a better than average hitting pitcher in his 15-year major league career, posting a.202 batting average with 73 runs, 18 doubles, 3 home runs, 47 RBI and 67 bases on balls.
