Dodgers left-hander Hyun-jin Ryu underwent shoulder surgery today that revealed damage in his labrum, manager Don Mattingly told reporters, including J.P. Hoornstra of the L.A. News Group (Twitter link). The labral repair surgery will end Ryu’s 2015 season without throwing a pitch, though Mattingly told reporters that the team’s expectation is that Ryu will be ready to pitch in Spring Training 2016.

The 28-year-old Ryu is earning $4MM in 2015 — the third season of a six-year, $36MM contract signed in the 2012-13 offseason. He’ll join right-hander Brandon McCarthy on the shelf for the duration of the season, leaving the Dodgers with just 60 percent of their projected rotation available for the rest of the year on May 21.

Clayton Kershaw, Zack Greinke and Brett Anderson will front the rotation moving forward, but Anderson’s injury history is among the lengthiest of any active pitcher in the league, so the Dodgers have to be at least somewhat concerned with their rotation depth moving forward. To this point, both Mike Bolsinger and Carlos Frias have pitched well as substitutes, but neither has any sort of track record in the Major Leagues.

Ryu projected as the Dodgers’ No. 3 starter this season after adjusting from the Korea Baseball Organization to Major League Baseball quite well from 2013-14. In those two seasons, Ryu worked to a combined 3.17 ERA with 7.7 K/9, 2.0 BB/9 and a 49.2 percent ground-ball rate. However, he failed to reach 200 frames in either of those campaigns, and he bothered by shoulder troubles in 2014, spending time on the 15-day DL early in the season and seeing his season end on Sept. 12 due to shoulder fatigue.

The Dodgers have a rich farm system that should afford them the ability to trade for rotation help if they see fit. Given the fact that the only starters who are guaranteed to return in 2016 are Kershaw, Ryu and McCarthy — Anderson is on a one-year deal, whereas Greinke has the ability to opt out of his contract’s remaining three years after the season — Los Angeles could is a speculative fit not only for rental pitchers such as Scott Kazmir, but for longer-term assets like Cole Hamels (if, of course, it is determined that trades are the best route).

The Dodgers have steadfastly refused to include Corey Seager, Julio Urias or breakout rookie Joc Pederson in trades to this point, and I’d imagine that will continue to be the case as the July 31 non-waiver trade deadline approaches. Nonetheless, the team has enough depth in the farm system that it will have a number of realistic targets to explore if president of baseball operations Andrew Friedman, GM Farhan Zaidi and VP Josh Byrnes elect to engage other clubs in trade talks.