In the Patriots’ 4-2-5 nickel and 4-1-6 dime packages, rookie Michael Buchanan has primarily been coming on as the right defensive end, kicking end Chandler Jones (the team’s best pass-rusher) to an interior rush position. Buchanan has lost containment in two of the last three games on third-down plays, which contributed to quarterback scrambles for first downs (Bengals’ Andy Dalton for 6 yards on third-and-5 and Jets’ Geno Smith for 14 yards on third-and-14). Carter’s presence could be tied, in part, to the Patriots looking for a more consistent player in that role.