Worth noting

• Nationals right-hander Doug Fister will throw on flat ground on Tuesday. He missed a start last week because of inflammation in his elbow. There is no timetable on when Fister will pitch in a game.

• Nationals right-hander Ross Ohlendorf threw on flat ground on Monday. It marked the first time he was able to throw a baseball since he suffered back spasms on Thursday against the Braves. Ohlendorf will throw again Tuesday. After that, he most likely will have a bullpen session before he gets back into a game.

• Left-hander Mike Gonzalez threw a bullpen session on Sunday and will pitch in a Minor League game on Tuesday. After that, Gonzalez will most likely pitch in a Major League game.

"I think he is prepared. We'll see how he comes out of [the Minor League game]," Williams said.

• Walters started at second base against the Astros on Monday, and Williams admitted that Walters was nervous about playing the position. Walters has spent most of his career as a shortstop and third baseman. In the third inning, Walters turned a double play on a ball hit by designated hitter Chris Carter. Walters will get another chance to play second in the next couple of days.

Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.