Kendrick's inconsistency continued in 2011, when he "flip-flopped between the rotation and the bullpen all season", performing as a spot starter and long reliever. His starts came during injuries to Blanton and Roy Oswalt, the latter of whom was a member of the "phour aces" that comprised the front-end of the Phillies' starting rotation (Oswalt, Cliff Lee, Roy Halladay, and Cole Hamels). When making those spot starts, he was able to "keep the team in the game". During the season, he improved against left-handed hitters, performed strongly against divisional opponents, and posted a career-best 3.22 ERA. Overall, he totaled 34 appearances, 15 of which were starts, and recorded an 8–6 record in 114 innings pitched. Again eligible for arbitration, this year, he signed a one-year, pact with Philadelphia.