Guerendo (pectoral) was placed on the reserve/PUP list, Jeremy Fowler of ESPN reports.
Guerendo spent all of training camp on the active/PUP list and is seemingly not ready to take the field, so he will remain on PUP and will miss at least the first four weeks of the season. As such, Kaelon Black and Jordan James will open as the top two options behind starter Christian McCaffrey (undisclosed).