"I could have played tonight," Walker said. "But with the day game [Sunday], we figured might as well give it one more night."
Added Pirates manager Clint Hurdle: "I think we have every feeling the swings went well tonight and if he feels good [Sunday], we'll have him back in the lineup."
Walker, 28, is hitting .277 this season with 16 homers and 50 RBIs in 97 games.
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. Stephen Pianovich is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.