New England signed Johnson to the active roster Saturday.
Johnson was initially elevated from the practice squad to the active roster Friday, but he'll get a spot on the 53-man roster after running back Terrell Jennings (concussion) was placed on injured reserve Saturday. Jennings will now be sidelined for at least the next four games, thus keeping him out for at least the remainder of the regular season. In his absence, Johnson will serve as the Patriots' No. 3 running back behind Rhamondre Stevenson and TreVeyon Henderson.