Depending on your perspective, the weekend is still going on, but here's what you may have missed so far.
On July 23, 1939, 9,772 fans flocked into Briggs Stadium to watch the Detroit Tigers host the Philadelphia Athletics, in what turned out to be a 16-3 victory for the home team. In the bottom of the 8th inning, the Athletics replaced starting catcher Frankie Hayes with Harry O'Neill. O'Neill was making his MLB debut, caught for one inning, did not make a plate appearance, and never again played in the big leagues.
Elmer Gedeon had a slightly more distinguished MLB career, though not by much.