The veteran quarterback will not participate in next week's workouts, and it's unknown when he'll return to action.

Stafford, 37, has not practiced since the Rams opened training camp while receiving treatment from trainers and the team medical staff for what McVay initially described as back soreness. McVay said last Tuesday that Stafford would sit out the first block of practices, but return on Monday when the Rams will be in pads for the first time.