The Freshman Athlete of the Year in 2016 in his first year playing at Desert Vista High School in Phoenix, Arizona, Eli Ankeney was a four-year letter winner who helped lead the Thunder to the playoffs in 2019, his senior year. Over the course of his four years there, the left-hander posted a 3.85 ERA in 123.2 innings, allowing 136 hits, walking 58, and striking out 152. In 2018, his junior season, the southpaw posted a 3.60 ERA in 48.2 innings with 52 hits allowed, 25 walks, and 63 strikeouts, and in 2019, his senior year, he posted a 3.