In 2017, LeVeon Bell had games with 170 and 179 rushing yards against Kansas City (that includes a playoff game played in January, 2017). Now he will be playing for KC. Who is the only other active running back who has run for over 170 yards against a team, then later joined that team's roster?
Adrian Peterson, who is currently on Detroit's roster. Peterson ran for 171 yards against the Lions in 2012, when he was with the Vikings. If we want to dive deeper, there's Lamar Miller. Playing for Miami, Miller ran for 175 yards against Houston in 2015, and later signed with that team. Miller currently is on Chicago's practice squad, so he's not quite an "active" player.