Samuel (ribs) wasn't participating at the beginning of Thursday's practice, Nick Wagoner of ESPN.com reports.
Samuel wasn't entirely absent Thursday, as Cam Inman of The San Jose Mercury News noted the wide receiver made his way to the 49ers' weight room following a walkthrough session. Ultimately, the team's second practice report of Week 4 will unveil whether or not Samuel was able to log some reps as he deals with rib and knee injuries.