Head coach Kyle Shanahan told reporters Tuesday that Stout's removal from Monday's 23-17 win over the Commanders was due to an AC sprain in his shoulder, David Lombardi of SFStandard.com reports.
Stout's practice reps during Week 6 prep were limited due to his shoulder injury. He was cleared to play Monday but was hampered by his injury, which led to Shanahan replacing Stout with Ashtyn Davis. Stout's practice participation over the coming days will provide some clarity on his status for Sunday's road game against the Falcons.