SOUTH BEND, Ind. (AP) -- Chicago Cubs right-hander Yu Darvish lasted just one inning in his rehab start with Class A South Bend on Sunday, casting doubt on his availability for the rest of the year.
Darvish, who has been sidelined by triceps and elbow injuries, shook his arm as he left the field after striking out Great Lakes' Romer Cuadrado with a 95-mph fastball for the last out of the first. But he said the first inning was great.
"I felt real good," Darvish said through an interpreter. "I didn't feel any abnormalities in that sense."
When Darvish warmed up for the second, he threw six pitches and winced on each one. Miguel Amaya, who caught Darvish's rehab start for South Bend on June 25, walked to the mound and summoned manager Jimmy Gonzalez and a trainer. After a short discussion, Darvish walked to the dugout.
"During warmups the next inning, I felt something in there," Darvish said. "Last time (in June) I did feel the same thing (but) I continued to throw. This time I stopped."
Darvish, who turned 32 on Thursday, signed a $126 million, six-year contract with Chicago in February. But he has made just eight starts in his first year with the Cubs, going 1-3 with a 4.95 ERA.
Darvish said he would ask for an MRI when he got back to Chicago. He wasn't sure if would miss the rest of the year.
"I can't really tell right now," Darvish said. "It depends how I feel tomorrow. I really want to come back this season. I am going to work hard and do my best to try and come back."
The Cubs are on top of the NL with a 71-52 record, but their rotation is looking a little thin. Mike Montgomery was placed on the 10-day disabled list on Friday with left shoulder inflammation, and Tyler Chatwood has struggled in his first year with Chicago after signing a $38 million, three-year contract over the winter.
The Cubs were optimistic about a possible return for Darvish after he threw about 55 pitches in a simulated game on Tuesday. But that optimism was likely wiped out by Sunday's rehab appearance.
Darvish allowed a first-pitch single and issued a walk, then retired three in a row. He totaled 19 pitches, 10 for strikes.
In his June rehab start for South Bend, Darvish allowed one run and three hits in five innings. His fastball reached 94 mph, but he complained afterward that his arm got tired as the outing went on.