PHILADELPHIA -- As a precaution, the Nationals decided not to start third baseman Ryan Zimmerman for the third consecutive game because of a tight left hamstring injury.

Before Wednesday's game against the Phillies, manager Jim Riggleman said there was a possibility Zimmerman could pinch-hit.

For the first time since Saturday, Zimmerman was able to take hitting and fielding practice Wednesday. It appears he didn't have any problems doing both. He did not participate in any running drills, which he hopes to do Thursday.

"I'm not sure how close he is to 100 percent, but we would like to get him real close before we put him back out there," Riggleman said.

Zimmerman said the hamstring is getting better and he hasn't taken an MRI. He also is not sure if he could pinch-hit.

"We haven't had any test or anything done [on the hamstring]. It's nothing crazy. We'll see how it feels today," Zimmerman said."There is no point in pinch-hitting if I can't score on a single."

Olsen to be called up, start Thursday

PHILADELPHIA -- The Nationals are expected to call up left-hander Scott Olsen from Triple-A Syracuse on Thursday and start against the Phillies that same day.

Olsen will replace Garrett Mock in the rotation. Mock was given one start to perform before he was optioned to Syracuse on Sunday. Asked if Olsen would have a longer leash, manager Jim Riggleman said, "We would like to win the ball game. That's the main thing. We hope he has a good performance, keeps us in the game and gives us a chance to win against a very tough club. We don't want to draw too many conclusions based on a game against Philadelphia."

A couple of days before the season started, Mock was picked over Olsen because of Mock's potential as a starter. Mock was told that he was on a short leash and the club would quickly call up Olsen if he didn't produce on the mound. There are some in the organization who feel Olsen is no more than a fifth starter.

The team also wanted Olsen to build arm strength after having shoulder surgery last summer. In his first start for Syracuse on Friday, Olsen pitched 6 1/3 innings and gave up four runs on eight hits. He didn't figure in the decision. While the numbers didn't look great, it appears that Olsen's fastball was back where it should be. It was clocked in the low 90s.

With Olsen being called up, the Nats have to take a reliever off the 25-man roster. The team will make an announcement before Thursday's game.

Riggleman not concerned with Marquis

PHILADELPHIA -- Nationals manager Jim Riggleman had a meeting with right-hander Jason Marquis on Wednesday afternoon, and the skipper told Marquis that he pitched much better on Monday against the Phillies, though he gave up six earned runs in 4 1/3 innings.

Riggleman looked at video and noticed that Marquis didn't have any problems keeping the ball down when he was in the windup. When Marquis was pitching from the stretch, the ball was up in the strike zone.

"I really feel he made a lot of good pitches," Riggleman said. "He pitched fine. We are up, 4-2. He goes out for the fifth. From that point on, the ball was up.

"For four innings, he kept the ball down and we are getting good results. But when he got into the stretch, the ball was up and that's not his style of pitching."

Though he has allowed 12 runs in 8 1/3 innings, Marquis didn't sound like a man who was concerned about his performance. He mentioned he has about 30 starts left to make up for his two disappointing outings and wants to help the team win ballgames.

"I'm not happy, but not concerned," Marquis said. "I know what I need to do to get back on track. It's just a matter of just doing it. It was a three-hitter stretch [in the fifth] that really changed the course of the whole game. From my recollection, there were pitches up in the zone. I just have to make better pitches. I have to get the ball consistently down in the zone."

Bruney not at Yankees' ring ceremony

PHILADELPHIA -- With a day off Tuesday, Nationals reliever Brian Bruney decided not to go to the World Series championship ring ceremony held at Yankee Stadium.

Bruney helped the Yankees win their 27th championship last year by going 5-0 with a 3.92 ERA in 44 games. Bruney said he preferred to stay with the Nationals in Philadelphia.

"I'm with the Nationals now," Bruney said. "My focus is here with these guys. Not being a member of the Yankees, I wouldn't want to be there. It's nothing against them or anything. It's an off-day, I didn't want to travel and do anything like that. I figure I will get [the ring] at some point. I waited long enough. I can wait a few more days."

Bernadina optioned to Syracuse

PHILADELPHIA -- Following Wednesday's 14-7 loss to the Phillies, the Nationals optioned outfielder Roger Bernadina to Triple-A Syracuse.

Washington did not make a corresponding move, but Bernadina said the Nats are calling up outfielder Justin Maxwell. According to Bernadina, general manager Mike Rizzo told him that the right-handed-hitting Maxwell was being promoted because the club will be facing a lot of lefties in the next week.

Maxwell was 5-for-15 (.333) with two RBIs for the Chiefs.

The left-handed-hitting Bernadina, 25, went 0-for-1 in one game with the Nationals after being recalled from Syracuse on Sunday.