Coach Kyle Shanahan said Monday that Thompson (ankle) is not expected back for Week 5, Cam Inman of The San Jose Mercury News reports.
Analysis:Thompson has already missed the 49ers' last two games with an ankle injury he picked up in Week 2 versus the Dolphins, and it seems like he's trending towards missing another contest come Sunday. In that case, Sebastian Valdez would be a candidate for increased snaps on the defensive line.
