A 6'3" 210 lb. right-handed pitcher, Keller is a native of Castaic, California and is a sophomore at the University of San Diego. Keller played baseball at West Ranch high school in Castaic where he was named pitcher of the year in both his Junior and Senior years. As a senior he went 7-3 with 61 strikeouts in 54 innings of work. He holds high school records for career wins (17), starts (24) and innings pitched (126) and was named to the Santa Clarita All-Area teams as a junior and senior. In his freshman season at San Diego, Keller made 12 appearances out of the bullpen, posting a 2-0 record with a 4.35 ERA and struck out eight batters in 10.1 innings pitched.