Arizona Cardinals safety Tyrann Mathieu and nose tackle Alamdea Ta'amu will begin training camp on the physically unable to perform list as they recover from last season's injuries.

Considered a risky pick after his legal troubles at LSU, Mathieu rehabilitated his image with a superb rookie season after the Cardinals drafted him in the third round. Mathieu's season ended in early December when he tore two knee ligaments while returning a free kick against St. Louis.

Ta'Amu tore his ACL in a season-ending loss to San Francisco. No timetable has been set for their return.

Arizona also released receiver Kelsey Pope on Wednesday.