Washington @ Houston preview

Last Meeting ( Jul 18, 2011 ) Washington 5, Houston 2

THE STORY: The Washington Nationals hope their recent dominance of the Houston Astros will help buoy their slim playoff hopes when the teams continue their three-game series Tuesday at Minute Maid Park. The Nationals won the opener 5-2 on Monday, their fourth consecutive win over the Astros.

TV: 8:05 p.m. ET, MASN2, Fox Sports Houston

PITCHING MATCHUP: Nationals RH Jordan Zimmermann (6-7, 2.66 ERA) vs. Astros LH J.A. Happ (3-11, 5.76 ERA)

Zimmermann finished the first half with a flourish, throwing 6 1/3 scoreless innings in a 2-0 win over Colorado on July 10. The 25-year-old has won four of his last five decisions and has allowed one run or fewer in six of his last eight starts. In his only start against Houston, Zimmermann allowed four runs (three earned) over 6 1/3 innings in 2009.

Happ was hit for five runs over 5 2/3 innings in his last start before the All-Star break, a 5-0 loss at Florida in which he matched a season-high with eight strikeouts. He has lost seven straight decisions and is winless since May 14, when he beat the Mets. The Nationals could provide the remedy for Happ's losing streak — in nine games (three starts) against them, he is 3-0 with a 1.14 ERA in 23 2/3 innings.

ABOUT THE NATIONALS (48-48): Washington has won just three times in eight games to slip nine games behind Atlanta in the wild card race, but it has outscored Houston 24-11 in the past four meetings. The Nationals activated Jerry Hairston Jr. on Monday, but he did not see action and hasn't played since July 1 because of a fractured right wrist.

ABOUT THE ASTROS (31-65): The Astros' dismal season continues, as they've lost 20 of 24 and have the worst record in the majors by seven games. Things haven't been any better at home, where Houston is a major-league worst 15-36. The Astros are without outfielder Jason Bourgeois, who is on a rehab assignment with a right quadriceps strain, and infielder Matt Downs, who is on the paternity leave list.

FINAL PITCH: When Mike Morse and Ryan Zimmerman hit home runs Monday for Washington, it marked only the second time in 17 games since June 27 that the Nationals hit multiple home runs in a game.