"The doc couldn't say if it was food poisoning or just a little bug. It was awful," Cozart said. "On Saturday night it was bad. I'm off today to get fluids in me as much as possible. I'm sure I'm still dehydrated, even after I drank a lot of water yesterday."
Cozart was disappointed, because he is 4-for-5 lifetime against Mets starter Shaun Marcum.
"I like facing Marcum," he said.
Manager Dusty Baker often gives his players an extra day off, even when they are feeling better, after an injury or illness.
"I really wasn't that surprised," Cozart said.
Cesar Izturis once again started in Cozart's spot.
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.