The White Sox selected Sims' contract from Triple-A Charlotte on Wednesday.
Sims fell short of winning a spot in the White Sox's Opening Day bullpen, but after striking out two batters over a scoreless inning in his lone outing at Triple-A Charlotte to begin the season, he's earned a quick call-up to the majors. The White Sox designated right-hander Jedixson Paez for assignment to clear a spot on the 40-man roster and in the bullpen for Sims.