Williams, a Waipahu High alum, hurt his ankle while swinging during an at-bat in the sixth inning of Washington's 6-2 loss to New York in 12 innings Saturday night. He singled in that at-bat and tweaked the ankle again when he wound up sliding hard into second base to try to break up a double play.

Williams went to the mound to begin the seventh, walked one batter, then was removed. Asked after the game if he thought the ankle was injured seriously enough to warrant time on the disabled list, Williams said: "No. Not at all."

But Sunday morning, he said, "just the whole left side of my left foot was just sore."

"It's not serious. It's mild," manager Manny Acta said Sunday. "But it's bothering him, and it was probably going to stop him from making his next start."

Until departing, Williams (0-4, 6.11 ERA) was enjoying by far his best start of 2007. He held the Mets without a hit for 5 1-3 innings.

"I felt like I was finally going to go forward and get out of this funk that I was in," Williams said Sunday, "and now this."

His next turn to pitch would have come up Thursday _ but the Nationals don't have a game that day, so the team shouldn't have to fill Williams' slot in the rotation for 10 days.

The likely candidate to fill in would be right-hander Jason Simontacchi, who appeared headed toward earning a roster spot until he injured his groin in spring training. Simontacchi went five innings Friday at Triple-A Columbus, and Acta said he'd need another rehab start to stretch out to seven innings.

King (0-0, 12.27 ERA) went on the DL on April 12 with left shoulder tendinitis and made one minor league rehab appearance.