This article was originally published on www.si.com as Sean McVay Unsure of Extent of Matthew Stafford's Lingering Back Injury.

Matthew Stafford will go through another lengthy workout Saturday to test his injured back before the Los Angeles Rams’ second preseason game.

Hampered by an aggravated disc, the veteran quarterback felt discomfort after trying a workout last weekend and wasn’t on the sidelines at practice this week.