Oldis was a catcher whose playing career lasted for 15 seasons, 1949–63. The native of Preston, Iowa, stood 6 feet 1 inch (1.85 m) tall and weighed 185 pounds (84 kg) and threw and batted right-handed during his active career. As a Major Leaguer, he appeared in 135 games as a second- or third-string receiver over all or parts of seven seasons (1953–55; 1960–63) with the Washington Senators, Pittsburgh Pirates and Philadelphia Phillies. He was a member of the 1960 World Series champion Pirates squad that beat the New York Yankees, serving as the club's third catcher behind Smoky Burgess and Hal Smith. Although he got into only 22 games during the 1960 season (three as a starting catcher), Oldis appeared in Games 4 and 5 of the World Series as a defensive replacement, spelling Burgess, but had no plate appearances. The Pirates won both contests, however, and went on to a seven-game upset on Bill Mazeroski's walk-off home run. Oldis' greatest number of games played was 47, in his final major league season.
For his MLB career, Oldis hit .237 with one home run—hit off Pete Richert of the Los Angeles Dodgers on August 9, 1962[1]—along with 22 runs batted in and 56 hits. Following his playing career, he was a coach for the Phillies (1964–66), Minnesota Twins (1968) and Montreal Expos (1969), and scouted for the Phils and Expos. He has been associated with the Marlins since 2002.