Zenner (back) was a full participant in practice Thursday, Tim Twentyman of the Lions' official site reports.
Zenner was never considered at much risk of sitting out Detroit's Week 1 tilt with Arizona, but after being upgraded from a limited participant in practice Wednesday to a full participant a day later, any lingering doubt about his status seems to have been eliminated. The 25-year-old is listed ahead of Dwayne Washington as the Lions' No. 3 back on the depth chart, but any edge Zenner holds over Washington as a short-yardage option is likely minimal.