Orewiler was originally selected in the 14th round of the 2015 draft by the Reds and advanced to Low-A in 2016. His 2015 season was spent exclusively as a reliever in rookie league, but then he transitioned into primarily a starter for Dayton in 2016. With the season transition, Orewiler saw his K/9 drop dramatically, but also his BB/9 did the same. He was allowing more hits through 12 appearances in 2016, but also saw his WHIP drop to 1.28. Orewiler only saw appearances in two of his four seasons on campus at Rice, and was primarily a reliever, but did make a few starts his final season.