In 2015, the Silver Spring, Maryland native made his Major League debut with the Arizona Diamondbacks on August 8th. He appeared in 18 games with the Diamondbacks that year, striking out 12 batters over 12 and 1/3 innings.

Hessler has split time between the AAA and MLB level since 2015 between the the Diamondbacks and San Diego Padres. Arguably the most impressive season of his professional career came with San Diego in 2016, appearing in 15 MLB games, while maintaining a 3.38 ERA to go along with nine strikeouts in 18.2 innings. 

This season, Hessler began his 2017 campaign with the Triple-A El Paso Chihuahuas in the Padres organization. The left-hander struck out 36 batters in 45.1 innings while maintaining a 4.57 ERA over 41 appearances with the team.

Hessler was orginially drafted by the Diamondbacks in the 28th round of the 2010 MLB June Amateur Draft out of Coastal Carolina Unviversity. The Padres claimed Hessler off of waivers from Arizona in May of 2016. 

Over the course of his seven-year professional career, Hessler has appeared in 304 games (35 starts), with 27 wins and seven saves while striking out 523 batters over 523.0 career innings and owning a 4.16 ERA.