Los Angeles Dodgers right-hander Yoshinobu Yamamoto was placed on the 15-day injured list on Sunday with right triceps tendinitis.

Dodgers right-hander Michael Grove (right intercostal strain) was also placed on the 15-day IL before the series finale against the visiting Kansas City Royals. Right-hander J.P. Feyereisen was recalled and right-hander Michael Petersen had his contract selected from Triple-A Oklahoma City.

"He'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," Dodgers manager Dave Roberts told reporters on Sunday. "His health is paramount. So for us to be proactive and put him on the IL seems like the smartest thing."

Yamamoto, 25, left Saturday's home start against the Kansas City Royals after throwing 28 pitches over two scoreless innings. His fastball velocity was in the 93-96 mph range, slightly off his season average during his two innings.

The Japanese hurler said he felt comfortable to start on Saturday.

"I did have tightness and I was aware of it (during the bullpen session), but it wasn't serious at that point. As I was pitching, it started growing," Yamamoto said through an interpreter, per ESPN. "I let coaches know, and we decided to pull me."

Yamamoto gave up one hit and a walk with one strikeout. Grove took over for Yamamoto.

Yamamoto was pitching on an extra two days of rest after his scheduled Thursday start against the Texas Rangers was pushed back.

He is 6-2 with a 2.92 ERA in 14 games (all starts) during his first year with the Dodgers after signing a 12-year, $325 million contract last December. He previously played seven seasons in Japan.