On May 15, 1940 — 1B Art Mahan and 2B Ham Schulte establish themselves as regulars at their positions with the Phillies. Fewer than a dozen players have been 120-or-more-game regulars in their only season in the major leagues, and the Phillies, again locked in last place, have two of them in one season. Neither Phillie will hit .250, but Schulte will top second basemen in fielding.

Source:
Baseball Reference May 15