O'Neill went 1-for-4 with a two-run home run in Saturday's 3-2 win over the Padres.
O'Neill slammed a two-run homer off Emilio Pagan in the eighth inning to give the Cardinals the lead. He has homered in back-to-back games and three of the last four. In his past 13 games, he has six long balls, 13 RBI and 13 runs scored. The 26-year-old is slashing .281/.350/.536 with 28 homers, 65 RBI, 73 runs and 12 steals in 427 plate appearances this season.