Born in St. Louis, Diering attended Beaumont High School and began his pro career in the Cardinals' organization in 1941, then missed the 1943–1945 seasons performing World War II service in the United States Army.

But he didn't win a regular job until 1949, when he was the Redbirds' starting center fielder, batting a career-high .263 in 131 games played.

Selected by the transplanted former St. Louis Browns in the 1953 Rule 5 draft, Diering resumed a regular role for the brand-new Baltimore Orioles in 1954 and 1955, getting into 265 total games.

After playing his final game as an Oriole on June 24, 1956, as a defensive replacement against the Detroit Tigers at Briggs Stadium,[2] he continued his pro career in the minor leagues into 1957.

In his 752-game, nine-season major league tenure, Diering collected 411 hits, with 76 doubles, 14 triples and 14 home runs.