ATLANTA — After leading the NL East for three straight months, the Atlanta Braves are trying to shake a late-season slump that could cost manager Bobby Cox a final postseason appearance before his retirement.

A 3-4 homestand left Atlanta three games behind Philadelphia in the division and leading the NL wild-card race by one-half game with 15 games remaining. The Braves entered September three games ahead of the Phillies.

The Braves, off on Thursday, begin a nine-game road trip on Friday at the New York Mets.

Atlanta held first place from May 31 through Sept. 6 and led by seven games on July 22. Poor hitting in crucial situations is a big reason the Braves have lost nine of 15 games in September.

"We haven't been playing our brand of baseball for a little while," said catcher David Ross after the Braves suffered only their second home series loss of the season. The last-place Washington Nationals beat the Braves 4-2 on Wednesday to win two of three games in the series.

"I don't think anybody's feeling like any pressure's getting to them," Ross said. "We all root for each other but when we don't get it done, we're disappointed. ... We're not playing bad but we're not playing our way right now."

Cox had a sharp response when asked after Wednesday's loss about the mentality of his team.

"The mentality of the team is great," Cox said. "We play them to win."

The Braves' struggles at the plate began soon after losing third baseman and No. 3 hitter Chipper Jones to a season-ending knee injury on Aug. 11. They have stranded 65 baserunners in their last nine losses, about seven per game.

For the season, the team is hitting only .238 with two outs and runners in scoring position. They rank third in the NL with their 3.60 ERA, but the lack of support has hurt the starters, especially Tommy Hanson.

Hanson, Atlanta's starter in Friday night's game at New York, has a 2.74 ERA since the All-Star break but is only 1-6 in that span, leaving him 9-11 overall.

"We offensively have got to produce enough to give our pitchers permission to have one bad inning," said outfielder Matt Diaz. "We can't put it all on our pitchers to be perfect every inning, that's for sure."

The Braves are only 31-41 on the road but must produce a winning road trip to keep their playoff hopes alive.

"When we have favorable pitching matchups, when we have home games, we have got to take advantage of every single one of them from here on out," Jones said this week. "If we don't, we could be looking from the outside in."

Braves general manager Frank Wren has made three trades in the last two months in attempts to help the offense. He acquired shortstop Alex Gonzalez from Toronto on July 13, outfielder Rick Ankiel from Kansas City on July 31 and first baseman Derrek Lee from the Cubs on Aug. 18.

Of the three, only Gonzalez has enjoyed the most success with Atlanta. He is hitting .263 with five homers and 31 RBIs in 57 games.

Ankiel has hit only .207 with one homer in 35 games as a part-time starter. Lee, expected to add power to the middle of the lineup, has hit only .241 with one homer and 12 RBIs in 24 games with the Braves.

The Braves have only six homers in 15 games in September.

The Braves' most consistent hitter late in the season has been rookie Jason Heyward. Heyward is hitting .419 (39 for 93) in his last 24 games. Overall, he is hitting .287 with 17 homers and 68 RBIs.

Atlanta's best chance in the NL East race is its six games remaining against Philadelphia.

The Braves play three games at Philadelphia on Monday through Wednesday. The Phillies end the regular season with three games in Atlanta on Oct. 1-3.

The Braves must play well on the road for the final weekend of the season to hold value.

Jones, who has remained with the team while rehabbing his knee injury, says it will be difficult to catch the Phillies.

"It's not going to be easy," Jones said. "They're at full strength. They're surging. It's going to be tough. I would feel differently if we were playing the same kind of baseball we were playing in May and June. Unfortunately, we're not."