“I feel comfortable that he can do it,” Manager Davey Johnson said. “He’s runs good. He’s really good defensively. He throws good. Smart player. But one of the things I do want to look at, I want to look at all the options we have. Maybe it’s a little early, but in my mind, it’s never too early to look at other things. This is the time of year when we need to look at some things.”

Werth has played only right field this season, but the Nationals did not just pluck the notion of Jayson Werth, Centerfielder out of thin air. He has played 104 games in center field during his career, starting 80 of those. Last season, when Phillies center fielder Shane Victorino landed on the disabled list, Werth played 21 games in center.

The UZR/150 metric, used by FanGraphs to measure a fielder’s defensive contribution to a team, which is admittedly flawed gauge over small sample sizes, judged that Werth’s defense in center field would have cost the Phillies 34.3 runs over 150 games compared to an average fielder.

The Nationals want to judge Werth’s defense for themselves, one of the motivations of playing him there this September. Manager Davey Johnson said Rick Ankiel could return to center tomorrow. But he also said, “I want to see what we’re capable of doing and what we’re not capable of doing.” The Nationals have tried to acquire a future center field this year, and if they fall short of landing one this season, they may see Werth as a potential option in 2012.

Werth, Johnson said, supports his move to center field. Last month, Johnson said, Werth approached him and told him, “If you need somebody in center field, I’m your man.” Johnson texted Werth this morning to let him know he would making the change to his position. Werth texted back, “I’m feeling good.”

With the promotion of Chris Marrero, Johnson also moved Michael Morse first base to left field. Johnson had previously said he wanted Morse to be accustomed to left field, his likely position in 2012 when Adam LaRoche returns from labrum surgery.

Morse last started in left May 18, and he said he has not recently been taking fly balls to stay sharp. “Whatever it says next to my name, I’ll play,” Morse said. “I’ll be first base coach.”

Morse can probably expect to play plenty of left field with Marrero in the fold. “Any time you call up a young player,” Johnson said, “you want to let him play. By and large, he’s up here to play.”

The shifting affected Rick Ankiel, who has not played in three consecutive nights after serving as the Nationals’ everyday center fielder all month. Johnson told Ankiel not to worry, but he may find himself with diminished playing time for the final month of the season.

“I think Ankiel would be the first to tell you, he’s pleased that he had a lot of playing time this year,” Johnson said. “I wanted to give other guys an opportunity to do some things. I want to see what we’re capable of doing and what we’re not capable of doing. We’ll go from there.”