Los Angeles Dodgers pitcher Hyun-Jin Ryu received a cortisone injection in his left shoulder on Monday and won't throw for at least four days. The team said that Ryu had an MRI with dye, which showed no changes from his previous MRI that was done in May. Ryu left his start on Friday after one inning, complaining of tightness and pain in his shoulder. The plan for Ryu is to skip his scheduled start Wednesday in Colorado to rest. Dodgers manager Don Mattingly didn't completely rule out Ryu being back in the rotation next week, but quickly added, ''I want to see how everything goes.