Samuel (ribs/wrist) won't take part in Thursday's practice, Matt Maiocco of NBC Sports Bay Area reports.
Samuel has yet to mix into drills this week due to two health concerns and thus may need to practice in some capacity Friday to avoid a designation ahead of Sunday's game at Arizona. With Brock Purdy (elbow) unlikely to play this weekend, Samuel will be on the receiving end of passes from Joshua Dobbs, assuming the wide receiver is active.