Washington (44-82) at Philadelphia (67-58)

The Philadelphia Phillies haven’t played their best recently, and it’s cost them their lead in the NL East. However, they still have the Washington Nationals’ number.

Philadelphia will look to extend its winning streak against Washington to seven on Wednesday at Citizens Bank Park, as the hapless Nationals try to avoid losing their 12th straight game overall.

The Phillies (67-58) held a 2 1/2-game lead over the New York Mets in the NL East as recently as Aug. 6. Two weeks later, Philadelphia trails the Mets by 1 1/2 games, largely due to a struggling offense.

Manager Charlie Manuel’s team is averaging barely more than three runs over its last 12 games, a span during which it is 5-7. Only two NL teams have averaged fewer runs in that stretch, with the Nationals (2.9) being one of them.

“I’m puzzled. I stay up late at night thinking about how we can get our offense going,” Manuel told the Phillies’ official Web site. “I’ll listen to what anybody’s got to say. Fans. Cab drivers. President Bush, anybody.”

Philadelphia only managed seven hits Tuesday, but one of those was Jayson Werth’s solo homer in the eighth inning to lift the Phillies to a 5-4 victory, their sixth in a row over Washington (44-82).

The heart of Philadelphia’s order - Chase Utley, Ryan Howard and Pat Burrell - went 2-for-11 with no RBIs as their recent struggles continued. The trio is hitting a combined .156 (19-for-122) with 14 RBIs since Aug. 7.

They’ll try to get going against Nationals rookie Collin Balester (2-5, 5.06 ERA). Balester won his major league debut on July 1, but has lost five of his seven starts since, including a 9-3 defeat to the Mets on Thursday, when he gave up five runs, four hits and five walks in six innings.

“I have to keep working in the bullpen to keep the ball down every single time,” Balester said after allowing two homers. “It’s killing me, keeping the ball up.”

One of Balester’s other losses came on July 29 against the Phillies, although he certainly pitched well enough to get a win. The 22-year-old right-hander yielded two runs over six innings but got charged with a 2-1 loss.

Washington, which has scored eight total runs in Balester’s last four starts, will look for better luck against Philadelphia’s Brett Myers (5-10, 5.02). The right-hander was 3-9 with a 5.84 ERA when he was sent to Triple-A at the end of June, but has been much better in five starts since returning to the majors.

He’s 2-1 with a 1.95 ERA in his last four outings. The loss came Thursday at Los Angeles, when he gave up three runs over seven innings and struck out eight, but took a 3-1 defeat.

“You pitch well when you win,” Myers said. “That’s the bottom line. I lost. I’m not going to be satisfied with any loss.”

Myers opposed Balester in the Phillies’ win on July 29, when he allowed one unearned run over seven innings. He’s 1-1 with a 3.00 ERA against the Nationals in three starts this season.