Ruiz got hit on the side of his batting helmet during a plate appearance in Thursday's 5-3 victory over Miami. He was placed on the DL on Friday.
"He'll be evaluated daily," Sandberg said. "He was just taking it easy [on Saturday]."
Todd Zolecki is a reporter for MLB.com. He writes a blog, called The Zo Zone. Austin Laymance is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.