The Los Angeles Dodgers could be without left-hander Hyun-Jin Ryu, their top starting pitcher so far this season, for a while after he strained his left groin Wednesday night in their 2-1 victory over the Arizona Diamondbacks. Ryu left the game in the bottom of the second inning after recording an out, and after manager Dave Roberts and a trainer came out of the dugout to check on him. It was the last pitch that probably got me,'' Ryu said through an interpreter after the game.