LOS ANGELES – Just replicating the performance of their starting rotation -- second-best in the majors to the Washington Nationals -- will be a major challenge for the Los Angeles Dodgers in 2015.It's hard to ask Clayton Kershaw to perform any better after a season in which he was a Cy Young shoo-in and a likely league MVP, leaving aside his performance in the postseason. Beyond Zack Greinke – who could opt out of his deal at the conclusion of next season – and Hyun-Jin Ryu, the Dodgers lack depth.