The Mets' Jose Valentin was going to head to New York for an MRI exam after leaving Saturday night's win over the Nationals in the fourth inning because of pain in the right knee. Valentin said he "felt a pop" while playing the field in the third inning, when he started to go to cover second on a Nationals steal attempt but then stopped. He stayed in, then left the field in the fourth, replaced by Damion Easley. "We don't think it's anything serious," said Valentin, who missed time after spraining his right knee in 2005.