McNichols signed a one-year contract with the 49ers on Tuesday, Jennifer Lee Chan of NBC Sports Bay Area reports.
McNichols missed all of the 2022 season with a shoulder injury and was non-tendered by the Steelers in March. The 27-year-old last suited up for the Titans in 2021, seeing 41 carries for 156 yards in 14 contents. He'll now work to earn a role in San Francisco's backfield.