He played in Major League Baseball (MLB) for the Chicago White Sox and San Diego Padres.

[7] Johnson spent the majority of 2014 in Charlotte, but made 5 more starts for the White Sox, struggling to a 6.46 ERA with 18 strikeouts across 23+2⁄3 innings.

[9] Johnson made only two starts for the White Sox to begin the 2016 season, and struggled to a 6.94 ERA with 11 strikeouts in 11+2⁄3 innings of work.

[10] On June 4, 2016, Johnson and Fernando Tatís Jr. were traded to the San Diego Padres in exchange for James Shields.

He split the year between the Double–A San Antonio Missions and Triple–A El Paso Chihuahuas, making 26 combined appearances and accumulating a 3.98 ERA with 45 strikeouts across 40+2⁄3 innings pitched.