Steve Heilenbach is in his second year with the ThunderBolts and second as a pro in 2019. He was the Bolts' first round selection in the 2018 Frontier League draft and signed on April 26, 2018. He pitched 9.1 innings over six appearances for the 2018 Bolts and allowed one earned run. Heilenbach was a four-year player at Illinois State University, where he pitched in 46 games (24 starts) and went 9-6 with a 3.36 ERA and 106 career strikeouts. He was named Second Team All-Missouri Valley as a senior in 2016 when he went 5-4 with a 3.30 ERA over 87 innings in 15 starts. Steve attended Lyons Township High School in La Grange, Illinois.