Who should i have for bench depth?

Im 12-1 in first place and have locked up a bye,here is my team.Qb-Rodgers,Rb's-S.jackson,Jacobs,Bl… and Westbrook,Wr's-Calvin Johnson,Nicks,Bowe,Ward,S.Rice,V.Jackson… question is should i drop Westbrook and pick up Roy Williams or Jonathan Stewart or stick with what i've got.Or any other suggestions for playoff run.!0 team league,regular scoring.