"We're optimistic Walker is fully back [from lower-back tightness] but don't know that. And we're still finding ways to [substitute on] defense for Pedro," manager Clint Hurdle said. "We need to have an extra infielder if [we have to make] both of those [moves] the same day."
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.