Nats, Phils play two at Citizens Bank Park

Jayson Werth was a key member of four straight National 10, but a lucrative contract offer from the Nationals this past winter leaves him out of the 2011 postseason.

Werth faces his playoff-bound former club today when Philadelphia and Washington start up a four-game series with a day/night doubleheader.

After missing all of 2006 due to injury, Werth joined the Phillies and hit .282 with 95 homers and 300 RBI over 543 games with the club, helping the franchise win a World Series title in 2008. However, a mounting payroll made it difficult for Philadelphia to keep the former All-Star and he eventually inked a seven-year, $127 million deal with Washington.

The 32-year-old failed to meet expectations this year as he is hitting just .230 with 19 homers and 56 RBI in 143 games.

He went 0-for-4 in Sunday's 4-3 victory over the Marlins, with Chien-Ming Wang hurling 6 2/3 innings to earn his first win since Aug. 16. Chris Marrero drove in two runs in Washington's sixth victory in eight games as well as its 42nd at home this year, a new single-season record since the club relocated in 2005.

Marrero will look to extend Washington's recent run of success in this series. The Nationals have won five of their last seven versus the Phillies, a modest run but on the Nats will look to build on after dropping 14 of the previous 17 encounters before this recent surge.

"He's just consistent," Jonny Gomes said of Marrero, who is hitting .280 with nine RBI in 21 games since getting called up from the minors. "He doesn't look overmatched."

Philadelphia, meanwhile, secured home-field advantage throughout the postseason despite a 4-3 loss to the Cardinals on Monday due to the Brewers' setback to the Cubs. The next goal for the club is the 100-win mark and the Phils would reach the mark for the first time since 1977 with a sweep of today's doubleheader.

Roy Halladay was denied his 19th win of the season after allowing four runs over eight innings in the loss to St. Louis. Philadelphia nearly took its starter off the hook, plating two runs in the ninth to get within one. However, Hunter Pence grounded out to third to end the game.

The Phillies suffered their second straight loss since clinching their fifth straight NL East crown on Saturday.

Kyle Kendrick gets the call in the day game as he makes his second straight spot start for Philadelphia in a doubleheader.

Kendrick hadn't pitched since Aug. 24 before starting the first game of a twinbill against the Marlins last Thursday. The layoff didn't hinder the right-hander, who took a no-hitter into the fifth inning before allowing a leadoff homer. Kendrick allowed just two hits over his five-inning outing, improving to 8-6 with a 3.22 earned run average in 31 games (14 starts) this season.

The 27-year-old is 2-3 with a 6.02 ERA in his career versus the Nationals and faced them as a starter on Aug. 19. He did not get a decision, allowing two runs over six frames.

Cliff Lee followed Kendrick in last week's doubleheader and will do so again tonight. The left-hander came one out shy of his seventh shutout of the season before yielding a game-tying solo homer to Jose Lopez with two strikes and did not get a decision over his nine-inning start.

"It was supposed to be a backdoor cutter. I left it up out over the plate," said Lee, who struck out 12. "He hit a home run. That's really it. I just made a bad pitch."

The 33-year-old still has a 0.56 ERA in his last eight starts and is 16-7 with a 2.38 ERA on the season.

Lee won his first three career meetings with Washington before a loss to the club on May 31, when he allowed six runs over 5 1/3 innings, yielding a pair of homers to Danny Espinosa.

Tom Milone faces Philadelphia for the first time when he makes his fourth career start opposite Kendrick in game one.

After not factoring into the decision of his first two starts, the 24-year-old southpaw beat the Mets on Thursday, allowing a run on three hits and three walks over 5 2/3 innings. He also got plenty of support in a 10-1 triumph.

"He had everything working," Nationals manager Davey Johnson said of Milone, who has a 4.60 ERA through his three starts. "He jammed a lot of guys."

Ross Detwiler, who will start the nightcap for the Nats, has gotten some additional rest as of late, but it didn't affect the Washington left-hander last Monday in a 3-2 win over the Mets.

Pitching for the first time since Sept. 2, Detwiler was charged with two runs on three hits and three walks over 5 2/3 innings. He moved to 2-5 with a 3.76 ERA in 13 games (eight starts) on the season, but is 0-3 with a 6.00 ERA lifetime versus the Phillies.