Herron signed with the Bills on Thursday, Chris Brown of the team's official site reports.
Herron will join a crowded backfield in Buffalo, as the team currently has six running backs on the roster in a group that is led by LeSean McCoy. A product of Ohio State, Herron is no stranger to the franchise, as the 27-year-old played in four games for the Bills in 2015, carrying the ball 11 times for 37 yards. After getting released in November, Herron finished up the year with the Colts, averaging 3.0 YPC over six games to finish the year. He'll now return to Buffalo to compete for a roster spot as backfield depth.