According to ELIAS

First month in MLB history with three rookies with eight or more home runs

Max Kepler
Max Kepler

Max Kepler hit a score-tying home run for the Twins in the sixth inning and singled in a run in the seventh inning of Minnesota’s 6-2 win over the Orioles. Kepler’s home run was his eighth this month, which ties Trevor Story for the second-most homers by a rookie in July, one behind the Padres’ Ryan Schimpf with nine. This is the first calendar month in major-league history in which three different rookies each hit at least eight home runs.