NEW YORK -- Nationals manager Jim Riggleman said his biggest regret during the 2010 season was not rotating the middle infield after the first month.

During that first month of the season, Riggleman used is a combination of Ian Desmond, Cristian Guzman and Adam Kennedy at shortstop and second base, while having a record of 13-10.

However, Cristian Guzman went on hot streak with the bat the next month and became the regular second baseman, while Desmond became the everyday shortstop. Kennedy ended up on the bench. However the Nationals struggled during May going 13-16. By the time he was put back in the lineup by late May, Kennedy was rusty -- offensively and defensively.

"The one regret I have for the season is, I kind of fell into the trap of how hot Guzman was earlier in the year," Riggleman said. "We were winning ballgames when Guzman, Kennedy and Desmond were in a rotation. But Guzman was so hot, I just fell into that trap of, 'He is so hot, I can't sit him, and Desi is doing a good job at short.'

"So I sat Kennedy for quite a bit. Guzzie kept hitting, but we weren't winning, so when I went back to Kennedy to get more involved, Kennedy was rusty and it took him a little while to get it going. That whole thing didn't work out. We were winning more games [when we had the rotation]. If I had to do it all over again, I would have rotated those three guys."

Dunn rests sore hamstring with eye on finale

NEW YORK -- Nationals first baseman Adam Dunn was out of Saturday's lineup against the Mets.

Dunn has right hamstring issues, but was available to pinch-hit. Dunn has been battling the problem for several weeks, but it hasn't stopped him from missing many games. The issues with the hamstrings started to flare up on Friday, according to manager Jim Riggleman.

"Last night, it was damp and cold," Riggleman said. "Before the game, I checked with him and the hamstrings were barking at him a little bit, and it didn't it get any better as the game went on. Hopefully, we will have him for the last game tomorrow. I'm going to try to stay away from him today."