Bjornson, 48, spent the past six seasons working in the Houston Astros organization, including five as bullpen coach on the major league staff (2012, '14-17) and one as minor league roving pitching instructor (2013). The former left-handed pitcher helped guide the Astros to the franchise's first World Series title in 2017, as Houston's bullpen ranked second in the majors in strikeouts per 9.0 innings (10.91), sixth in opponent batting average (.234), and 10th in WHIP (1.28). Over the past four seasons (2014-17), Astros relief pitchers posted the highest strikeout-to-walk ratio in the majors (3.17).
Prior to joining the Astros, Bjornson spent 13 seasons (1999-2011) as a pitching coach at the minor league level in the Montreal Expos, Kansas City Royals, Washington Nationals, Los Angeles Dodgers, and Colorado Rockies organizations. In addition, he served as pitching coach for the Occidente Pastora de los Llanos of the Venezuelan Winter League for four seasons from 2000-03.
Born in Tucson, AZ, Bjornson pitched at Arizona Western College and Nicholls State University. After signing with the Astros as a non-drafted free agent, he appeared in 81 minor league games (27 starts) from 1991-93, posting a 3.82 ERA (109 ER/257.0 IP) with nine wins and three saves. He currently resides in Tucson.