Beginning his professional career with the Gulf Coast Reds, Roenicke pitched 8 innings and gave up only one run.

Roenicke made his major league debut on September 13, walking, striking out, and hitting 1 batter each.

[1] On July 31, 2009, he was traded to the Toronto Blue Jays along with Edwin Encarnación and Zach Stewart, in exchange for Scott Rolen and cash considerations In 2 seasons with the Blue Jays, Roenicke went 1–0 with a 6.38 ERA in 29 games On June 2, 2011, Roenicke was claimed off waivers by the Colorado Rockies and was optioned to Triple-A Colorado Springs.

Roenicke signed a minor league contract (including a spring training invitation) with the Washington Nationals on February 14, 2014.

He split the year between the High–A Inland Empire 66ers, Double–A Arkansas Travelers, and Triple–A Salt Lake Bees, accumulating a 3.80 ERA with 49 strikeouts across 31 relief appearances.

[7] He finished the season with a 7–5 record and a 2.70 ERA in 20 starts for the Pericos, getting selected to the Mexican League All-Star Game (South Division) and carrying the club to its second consecutive championship appearance.

[12] Roenicke, who grew up in Nevada City, California, comes from a baseball family as his brother Jason played in Toronto's minor league system in 2008–2009, his father Gary played 12 major league seasons from 1976 to 1988 and is currently a scout in the Baltimore Orioles organization,[13] and his uncle Ron played 8 seasons from 1981 to 1988 and was previously the manager of the Milwaukee Brewers from 2011 to 2015 and the Boston Red Sox in 2020.