Ryu had his spring debut delayed by back soreness that so concerned the Dodgers they ordered the left-hander to undergo an MRI exam last month.
That test showed no structural damage and after his two-inning outing Thursday, Ryu again said there was nothing to be concerned about.
"Obviously, my health is good right now. I'm not worried," he said through an interpreter. "I'm very confident my next game will be [three] innings."
"Most guys, all you really worry about is arm strength," Mattingly said. "He threw enough [that] we were comfortable.
"And he always throws the ball where he wants so you don't really worry about his location."
Ryu threw 30 pitches Thursday, 22 for strikes, and gave up just one hard-hit ball:
Ryu, who turns 28 later this month, was sidelined three times last season, twice with shoulder problems and once with a strained gluteus muscle. He still managed to make 26 starts, going 14-7 with a 3.38 earned-run average.
"Today was more like preparing for the regular season, for me to get healthy and see my pitch count [increase]," Ryu said. "I didn't even really think about the regular games.
"It was more for … focus."
Over and out
Joc Pederson's ninth-inning home run was the only run the Dodgers needed. But in addition to it being a game-winning hit, what also made the blast memorable was that it sailed over — way over — comedian Will Ferrell, who had entered the game in right field for San Diego to start the inning as part of an HBO project that will also raise money for the fight against cancer.
"I think it's great," Pederson said. "It's raising awareness. Anything to help … to find a cure and save some lives. I'm all for it. What he did was bigger than baseball."
Matt Kemp spent all nine of his big league seasons with the Dodgers before being traded to San Diego in a five-player deal in December.
He made his first appearance against his former team Thursday, bouncing back to the mound in the first inning, lining out to right field in the fourth and striking out in the seventh.
"It was very unique," a smiling Ryu said of facing Kemp. "Who would have thought that I would have experienced something like this? But it was just another hitter. That's what I thought and that's how I treated him."