In 1938, he joined the United States team under international baseball proponent Leslie Mann to compete in the inaugural Amateur World Series in England.

He missed the 1944 and 1945 seasons while serving with the United States Navy in the Pacific Theatre of World War II.

[1] Selected off waivers by the Chicago White Sox from the Cubs on April 20, 1946, Platt played in 84 games that year, hitting .251 with three home runs and 32 RBI in 247 at-bats.

[2] When the Browns faced black pitcher Satchel Paige of the Cleveland Indians in 1948, Platt told manager Zack Taylor that he would not play against him.

[3] In 1953, he managed the West Palm Beach Indians for the beginning of the season, being replaced eventually by Bubba Harris.