The Royals recalled Hoffmann from Triple-A Omaha on Friday.
Hoffmann made his MLB debut earlier this season, allowing two runs in two innings of relief May 30. He'll take the spot of Michael Lorenzen (oblique) on the 26-man roster, although Hoffmann will work out of the bullpen rather than plugging the hole in the rotation. Hoffmann boasts a 2.31 ERA and 55:10 K:BB in 39 innings with Omaha.