Samuel (hamstring) returned to practice as a full participant Friday, Nick Wagoner of ESPN.com reports.
Samuel's ability to take every rep at Friday's session confirms his absence from practice Thursday was precautionary, just as head coach Kyle Shanahan suggested was the case. The second-year wideout shouldn't face any limitations versus the Bills on Monday, when he'll be looking to build on the season-best performance he submitted in the 49ers' Week 12 win over the Rams (11 catches for 133 yards on 13 targets).