Samuel (ribs/knee) is running on the side during Friday's practice, Nick Wagoner of ESPN.com reports.
It's better than nothing but doesn't necessarily mean he'll be listed as a participant in practice. Samuel missed Wednesday and Thursday, while Brandon Aiyuk (shoulder) has been practicing all week after missing the 49ers' Week 3 win over New York. The team figures to have at least one of them available -- which should be enough -- this Sunday against Arizona.