(From The My Sportsbook - All Times Eastern)

PROJECTED PITCHING MATCHUPS

May 17, 8:05 p.m. - Javier Vazquez (4-2) vs. Roy Oswalt (4-4)

May 18, 8:05 p.m. - Russ Ortiz (3-2) vs. Andy Pettitte (2-4)

May 19, 8:05 p.m. - Brad Halsey (2-2) vs. Roger Clemens (2-1)

2004 SEASON SERIES: Houston won, 4-2

ARIZONA (23-16)

The Diamondbacks try to keep their momentum going in this series. Arizona has won two straight heading in, and is 5-1 in its last six overall. The D-Backs are currently tied with San Diego for first place in the National League West. In the opener the D-Backs will go with Javier Vazquez, who is 4-0 in his last five starts. Last Wednesday he picked up a no-decision in a 3-2 win over Washington, allowing two runs on six hits in seven innings, striking out seven and walking none. Lifetime versus the Astros, Vazquez is only 2-3 with a 4.50 ERA in nine starts.

Vazquez leads the National League with a 1.4 walks per nine-innings ratio, and hasn't issued a free pass in his last three outings. Vazquez is 4-0 with a 1.89 ERA the last five times he has taken the hill.

On Sunday, Craig Counsell's seventh-inning homer put Arizona ahead and Alex Cintron's RBI double in the eighth proved to be the difference, as the Diamondbacks beat the Colorado Rockies, 5-4, in the finale of a four-game set at Coors Field. Cintron ended 2-for-4 with two RBI for the Diamondbacks, who won two straight and three of four from the Diamondbacks. Counsell also had two hits for Arizona.

The D-Backs' Troy Glaus is tied with the Mets' Cliff Floyd and the Reds' Adam Dunn for the National League lead with 11 home runs.

HOUSTON (14-23)

Roy Oswalt toes the rubber for the Astros in the opener, trying to snap a two- game losing streak. Last Wednesday in Florida he allowed two runs on five hits in 7 2/3 solid innings, but Houston lost, 2-1. Oswalt has lost three of his last four outings overall on the heels of a three-start winning streak. Lifetime against Arizona, Oswalt is 3-0 with a 1.23 ERA in three starts.

For the Astros on Sunday, Morgan Ensberg belted three home runs and Brandon Backe tossed his first career shutout, as Houston downed the San Francisco Giants, 9-0, in the finale of a four-game series at Minute Maid Park. Ensberg finished 4-for-4 with a career-high five runs batted in for the Astros, who won the final two games of the series to earn a split. Houston posted victories in back-to-back games for the first time since winning three straight from April 30-May 2. Craig Biggio also hit a two-run homer and ended with three RBI for the Astros.

Houston is 12-7 at home, as opposed to its horrible 2-16 road mark.

Astros starting pitchers have not allowed more than two earned runs in any of the last seven games.