A catcher, Thacker's pro career extended for 13 seasons and included the entire 1962 campaign and parts of four others in Major League Baseball for the Chicago Cubs (1958; 1960–62) and St. Louis Cardinals (1963).

[1] Thacker was born in Louisville, Kentucky, and signed with the New York Yankees in 1952 after his graduation from duPont Manual High School.

In the third at bat of his debut game August 3 at Connie Mack Stadium, he hit a home run off Seth Morehead of the Philadelphia Phillies to help the Cubs out-slug the Phils, 12–10.

[2] Two days later, in his third MLB game, he hit another solo shot, this time against Stu Miller of the San Francisco Giants, helping the Cubs hang on to win another slugfest, 10–9 at Wrigley Field.

Facing Baseball Hall of Famer Sandy Koufax—and catching another Hall-bound pitcher, Bob Gibson—Thacker struck out in his only two plate appearances.