The 25-year-old right-handed pitcher was drafted by the Nationals in the 45th round of the 2011 MLB June Amateur Draft from Oklahoma Baptist University. Mirowski spent four seasons in the Nationals system and owned a career 17-6 record and a 2.37 ERA in 163 1/3 innings. The native of San Mateo, CA has pitched his entire career from the bullpen. In 101 relief appearances, he totaled 183 career strikeouts and registered a 3.45 strikeout-to-walk ratio.
Mirowski earned several promotions throughout his impressive career in affiliated baseball. After just 12 games with the Potomac Nationals in 2014, he earned his second promotion to Double-A Harrisburg. He appeared in 10 games and recorded 12 strikeouts in 13 innings of work with the Senators last year.
In 2013, Mirowski went 8-3 with a 1.50 in 23 games for high Single-A Potomac. In 48 innings, Mirowski had 59 strikeouts and 11 walks yielding a .180 opponents’ batting average. Following his first career call up with the Senators in 2013, he struck out 29, walked four and held opponents to a .197 batting average in 20 2/3 innings.
Shortly after the 2013 campaign, he pitched in the Arizona Fall League for the Mesa Solar Sox. With the Solar Sox, he posted a 2.25 ERA and had 10 strikeouts and issued two walks in nine games.
Mirowski began his affiliated career in 2011 with the Auburn Doubledays and pitched back-to-back seasons for the members of the New York Penn League. After four games with the Doubledays in 2012, he was called up to the Nationals Class-A Hagerstown Suns where he manufactured a 2.00 ERA in 16 games.