Yu Darvish ended a minor league rehab start early on Sunday and requested an MRI after the Chicago Cubs' right-hander again experienced discomfort in his pitching elbow.

Darvish, who has been on the disabled list since May 23 with right triceps tendinitis, tossed 19 pitches in the first inning for Single-A South Bend but asked to come out during the second-inning warm-up.

The 32-year-old Japanese said the pain was similar to what occurred in his last minor league start on June 25, after which he was diagnosed with right elbow inflammation.

"During the warm-up of the next inning, I felt something in there," Darvish said through an interpreter. "Last time, even though I did feel the same thing, I continued to throw. This time, I just stopped it here."

Darvish, along with Cubs' manager Joe Maddon and president of baseball operations Theo Epstein, had been encouraged by a 55-pitch simulated game Wednesday at Wrigley Field, indicating the right-hander was ready to take the next step in his recovery.

"I'm disappointed in myself more than anything," Darvish said. "It depends on the examination, but I'll give it my all and try to make a comeback with all my strength."

In eight starts with the Cubs this season, Darvish is 1-3 with a 4.95 ERA. He signed a six-year, $126 million deal with the club in February, but has not pitched since May 20.