We don't exactly know what his injury was, but initial reports had it as plantar faciitis which is not something you'd incur from one practice. Maybe that would qualify as a NFI injury. Beats me, but if my point was really that we don't know if they really want to keep Cooper.
Having had plantar fascitis, it can be overcome when recognized and treated. Only takes a little time and Cooper has been at it for 5 weeks already.