As the rest of their teammates went through stretching and position drills, three Detroit Lions spent the early part of NFL training camp practice Tuesday in Allen Park working on the back field alone with a trainer in the end zone.
Marvin Jones, who is on the nonfootball injury list with a back injury, ran sprints full speed the width of the field. Jameson Williams, who left early in Monday's practice with a leg injury, did some light resistance work. And C.J. Gardner-Johnson stretched in place and walked gingerly through a backpedal.