Zenner agreed to a deal with the Lions on Tuesday.
Zenner was waived from injured reserve by the Lions in September, but now seemingly fully healthy, rejoins his former squad. In three years with the Lions, Zenner rushed 119 times for 420 yards and five touchdowns. The 27-year-old won't likely see the field much, as he's expected to be buried on the depth chart behind Kerryon Johnson, LeGarrette Blount and Theo Riddick.