"He's throwing well," Yost said. "He felt just a little bit of [numbness] in one small area in his hand so we'd like that all cleared up before he comes back up. He'll rest, throw a side, and we'll evaluate then. But I think he'll probably make one more rehab start."
Meanwhile, left-hander Jason Vargas, also on the disabled list, threw a simulated game of about 40 pitches on Thursday.
"I would think he'll throw another simulated game or two and we'll go from there," Yost said. "He looked good. Getting close."
Jeffrey Flanagan is a reporter for MLB.com. Follow him on Twitter at @FlannyMLB. This story was not subject to the approval of Major League Baseball or its clubs.