The Los Angeles Dodgers shut down Hyun-Jin Ryu's throwing program and sent him back to Los Angeles after he experienced discomfort in his left shoulder when he tried to play catch Sunday.

Ryu will begin the season on the disabled list.

"I think he's feeling something. If he was feeling nothing, we wouldn't be trying to get him in front of Doc," Don Mattingly said. "We know to move forward it's going to be a heavier workload, so we've got to be sure where we're at. I saw the look on Hyun-Jin's face and it wasn't typical Hyun-Jin."

Ryu (28-15 with a 3.17 ERA in two seasons) experienced soreness in his shoulder the day after a March 17 start against the Texas Rangers and had an anti-inflammatory injection the next day.