LOS ANGELES -- After leaving his Saturday start early due to what was first believed to be right triceps tightness, Yoshinobu Yamamoto went on the injured list for the first time in his MLB career with a strained rotator cuff in his right shoulder. The injury is not expected to be season-ending, but he will be out for at least a few weeks.

Both Yamamoto and right-hander Michael Grove (right intercostal strain) were placed on the 15-day IL ahead of Sunday’s series finale against the Royals at Dodger Stadium. As the corresponding moves, the Dodgers recalled right-hander J.P. Feyereisen and selected the contract of right-hander Michael Petersen from Triple-A Oklahoma City.

Yamamoto’s issues started during his previous start at Yankee Stadium. Yamamoto threw a season-high 106 pitches, including his 19 hardest pitches of the season, consistently getting to 97-98 mph with the four-seam fastball. He also threw 13 sliders against New York, his most in a Major League game.

There is no immediate timetable for Yamamoto’s return, though manager Dave Roberts said the right-hander will not throw for the next couple of weeks. He added that Yamamoto’s MRI did not reveal any tears.

Yamamoto, who signed a 12-year, $325 million contract over the offseason, is a key part of L.A.’s rotation plans. And he has started off strong, pitching to a 2.92 ERA through his first 14 games. But there is much to navigate with the 25-year-old rookie in his transition from NPB to MLB. That includes the Dodgers going to great lengths to get him additional days of rest between starts beyond MLB’s traditional four, keeping more in line with the norms of Japanese baseball.

“I just think that it's a guy that we're still trying to learn a lot about and appreciate the fact that the most important time of the season is yet to come,” said Roberts. “And his health is paramount. So for us to be proactive and put him on the IL, kind of reset him, seems like the smartest move.”

The Dodgers have someone ready to fill Yamamoto’s slot, as right-hander Bobby Miller (right shoulder inflammation) is scheduled to come off the IL to start against the Rockies on Wednesday at Coors Field. The team had been planning to temporarily use a six-man rotation, but that won’t be necessary for the time being. That could, however, come into play again when Clayton Kershaw -- who is ahead of schedule in his rehab from left shoulder surgery and about to begin a rehab assignment with Single-A Rancho Cucamonga -- is ready to return.

“Part of constructing the roster is getting an abundance of starting pitching,” said Roberts. “It's just in baseball everywhere, guys go down at different times, and you've got to be able to backfill.”

Yamamoto’s short outing on Saturday forced the Dodgers’ bullpen to cover seven innings, and Grove was first up, having to get warm in a hurry to handle the third and fourth. Grove has primarily filled a long relief role with L.A. this season, also serving as an opener on two occasions. At present, the Dodgers expect it to be a short-term absence for Grove. Last season, he missed a month and a half with right lat tightness.

Feyereisen and Petersen provide reinforcements to the taxed relief corps. It will be Feyereisen’s third stint with Los Angeles this year. Petersen, 30, will be making his MLB debut when he gets into a game. In 23 appearances with Oklahoma City this year, he has a 1.61 ERA with 31 strikeouts and six walks in 22 1/3 innings.

“He's a good man,” Roberts said of Petersen. “I'm excited for him. He's had to earn his way to the big leagues. Wasn't a prospect recently. And he just had to continue to perform. When he takes the mound, you should see 98-100 [mph]. He's been working on his breaking ball. But my message to him is, ‘Keep the blinders on and attack.’”