LOS ANGELES -- Yu Darvish threw a bullpen session on Thursday and still has pain in his right triceps muscle, so he won't be returning to the Cubs rotation this weekend. What's next? The Cubs aren't sure.
"It didn't go that well and he was not able to cut it loose," Cubs manager Joe Maddon said after Darvish's workout at Dodger Stadium. "We'll re-evaluate once we go back to Chicago and let you know the next step. For right now, he's not going to be able to pitch on Saturday."
The Cubs were encouraged after Darvish threw five innings in a Minor League rehab outing on Monday with Class A South Bend and had hoped he could start in an Interleague series against the Twins this weekend. Instead, Tyler Chatwood, who was activated from paternity leave on Thursday, will start Saturday and be followed by Jonathan Lester on Sunday.
"He threw really well in South Bend," Maddon said. "Prior to that, he'd pitched at [Wrigley Field] in a sim game and threw really well. Between then and now, it just doesn't feel right.
"He said there was more pain today," Maddon said.
Darvish, on the disabled list with right triceps tendinitis, is 1-3 with a 4.95 ERA in eight starts in his first season with the Cubs after signing a six-year contract in February.
"It's one of those things -- you've got to work through it," Maddon said.
News and notes 
• After his abbreviated outing of 2 2/3 innings on Wednesday, Cubs starter Kyle Hendricks said he was "searching" for an answer. Maddon said it was puzzling to see the right-hander struggle.
"The strange part is, he's throwing the ball harder," Maddon said. "His arm feels great. I'm watching from the side and when I see him hitting 90 [mph] on a gun, that's about his limit. Physically, he feels good.
"The changeup has not been as effective. It's kind of a paradox -- it looks like he feels great but the results aren't there."
• Dillon Maples was optioned to Triple-A Iowa to open a roster spot for Chatwood. Maples struck out three in his two innings of relief work on Wednesday.

"Jason Heyward came in from the outfield and he was raving [about Maples]," Maddon said. "[Heyward] said, 'You don't realize how much that ball was moving.' It seems to me he's fitting into his Major League skin better. He looked relaxed out there and you could see it in the dugout. We'll get him back up here because that stuff there is really high end."
• C.J. Edwards, on the disabled list with right shoulder inflammation, will make a Minor League rehab outing Friday with Iowa.
• Third baseman Kristopher Bryant, on the disabled list because of a sore left shoulder, has yet to resume baseball activities.