Detroit listed Arnold (shoulder) as a full participant on Wednesday's estimated practice report.
The Lions didn't hold an official practice Wednesday, but Arnold's estimation as a full participant indicates that he is past a shoulder injury that caused him to miss the two games prior to Detroit's Week 8 bye. Unless he suffers a setback over the next two practices, Arnold is in line to make his return against the Vikings on Sunday. His return would bolster a Lions secondary that is dealing with injuries to Kerby Joseph (knee) and Avonte Maddox (hamstring).