"Veras is a little sore with his left oblique, and hopefully he'll be OK," Renteria said. "He's been working really hard and developed a little soreness. He's a very hard worker. We'll monitor it and see how he's doing."
The Cubs have eight relievers in the bullpen, including Veras, after adding lefty Zac Rosscup and right-hander Neil Ramirez on Thursday.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.