Diamondbacks pitcher Robbie Ray left Sunday's 3-1 loss to the Nationals in the second inning because of a strained right oblique.

After throwing a pitch to Washington's Matt Wieters, Ray called the trainer from the dugout and began motioning toward his right side. He exited the game after a brief conversation with the trainer and manager Torey Lovullo.

"I felt great up until that one pitch," Ray said. "I was probably in the middle of my delivery, I was letting go of the ball and just felt my side grab, and I wasn't able to finish the pitch and left it up and away. I just wasn't able to get anything on it."

Lovullo said Ray will undergo an MRI on Monday.