O’Leary has earned a batting average of .226 for his career in baseball with 317 runs scored and an OPS of .386. In his time in the Majors, he approached the plate 3,607 times and has reached base with a base hit 731 times. He has accumulated a slugging percentage of .116 in addition to earning 880 bases. For his career, O’Leary has hit 3 balls out of the park while knocking in 220 runs. He has gone down on strikes 247 times and has taken a walk on 164 occasions, contributing to a .270 OBP.