Halladay gets the nod this afternoon in the finale of a three-game series at Minute Maid Park and is 12-2 with a 2.55 earned run average in his last 20 starts. The Phillies are 16-4 over that stretch, but have lost three in a row for the first time since dropping a season-high four straight games from May 31-June 4.
The Phils' magic number to clinch a postseason berth is still one, the same number of wins Halladay has in three career starts against the Astros. He is 1-1 with a 1.64 earned run average in this matchup and defeated Milwaukee his last time out in a 5-3 victory on Friday. He allowed only a run and four hits in eight innings to improve to 17-5 with a 2.44 ERA in 29 starts. The right- hander is 9-3 in 15 road starts.
Hamels failed in his bid for a 15th win on the season in last night's 5-2 loss, as the left-hander was reached for five runs -- four earned -- and nine hits in five innings. Hunter Pence homered again against his former team and Carlos Ruiz went deep for the NL East-leading Phillies, whose magic number to clinch a fifth straight division title is five.
"We got outplayed again," Phillies manager Charlie Manuel said. "We were taking things for granted. ... We're much better than that."
Philadelphia is 11 games ahead of Atlanta in the NL East and can also punch its ticket to the playoffs with a St. Louis loss. It would be the earliest point in the season the franchise has clinched a playoff spot, as the 1915 ballclub did it in 147 games.
After Wednesday's matinee the Phillies will return home for a 10-game residency versus the Marlins, Cardinals and Nationals. The Phils haven't been swept in a series of three or more games since the Astros won all four meetings in the City of Brotherly Love from Aug. 23-26, 2010.
Houston has won two straight and three of four games, and has received a big lift from two former Phillies pitchers so far in this series. Brett Myers pitched the Astros to victory in Monday's series opener and J.A. Happ followed suit last night with six innings of one-run ball, four strikeouts and four walks. He is 6-15 on the season.
"He did a real good job of keeping his emotions under control," Astros manager Brad Mills said of Happ, who was traded by the Phillies to the Astros in the Oswalt deal last season.
Clint Barmes hit a three-run homer and J.B. Shuck recorded three hits for Houston, which will start a six-game road trip Friday against the Cubs and Reds. The Astros have won nine of their last 13 home games.
Bud Norris gets the nod for the 'Stros today and he's 6-9 with a 3.78 ERA in 29 starts this season. Norris is 0-1 in his previous four trips to the mound and threw seven decent innings in Friday's 4-3 loss at Washington, surrendering three runs -- two earned -- and five hits. He lost to the Phillies on April 3 this season and is 1-2 with a 5.30 ERA in four career starts against them.
The right-hander has made 16 home starts in 2011, going 4-5 with a 3.90 ERA.
Philadelphia swept a three-game series against Houston earlier this season from April 1-3 at Citizens Bank Park.