The move comes as a reaction to the Lions' other transaction from Wednesday. Detroit has officially placed Tyrunn Walker on the injured reserve list after breaking his fibula during Monday night's game.
Fluellen has played in seven previous season with the Lions, including eight games in 2014. He has earned 39 tackles and 4.5 sacks over his career. He will likely immediately jump into the lineup, as Detroit's defensive line depth is now perilously thin with Walker gone, and Haloti Ngata struggling with an injury of his own.