SAN FRANCISCO -- Dodgers pitcher Hyun-Jin Ryu will undergo arthroscopic left shoulder surgery on Thursday, and manager Don Mattingly expects it to be season ending.
The Dodgers have not disclosed what damage Dr. Neal ElAttrache expects to find, but they have said recent MRIs revealed nothing new, a nice way of saying that whatever he has now he had before. Ryu pitched 1,269 innings in seven seasons in Korea, then another 344 in two seasons with the Dodgers.
Mattingly was asked if there was an outside chance Ryu could return late in the season and said: "I don't get that feeling."
So, Ryu joins Brandon McCarthy (Tommy John surgery) to put 40 percent of the Dodgers' starting rotation on the shelf.
Ryu hasn't pitched since Spring Training because of left shoulder impingement that has not responded to conservative treatment. He has played catch and thrown bullpen sessions, but twice was shut down with continuing discomfort.
Ryu was sidelined by shoulder tightness twice last year. It cropped up again after his second Spring Training start in March. A cortisone injection didn't resolve the discomfort in the shoulder, which often is a symptom of labrum damage.
"Replacing those innings is not an ideal situation," Mattingly said. "It's an opportunity for Frias and Bolsinger and guys like that. It's a test for the club as far as depth. Every team deals with some measure of injury. Starting pitching is the toughest to deal with."
Club president Andrew Friedman said on Tuesday that he is looking to trade for a starting pitcher. Another possible option is Brandon Beachy, who is recovering from a second Tommy John operation.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.