Jason Marquis has faced Houston more than any other opponent in his 12 Major League seasons, having spent five seasons in the same division while with the Cardinals (three years) and Cubs (two years).
On the other side will be 20-year-old right-hander Jordan Lyles, who is seeking his first career win in his ninth start.
Lyles has gone 0-4 with a 4.60 ERA. The last Astros pitcher to go at least eight straight winless starts to begin a season was Felipe Paulino, who went 10 starts without a win from April 10-May 30 last season.
Marquis, who earned his first big league victory in 2000 as a 21-year-old member of the Braves, is 7-4 with a 4.05 ERA in 18 starts this season. He took the loss in his last start, which came in a 2-1 defeat to Ubaldo Jimenez and the Rockies.
"I thought I threw the ball well," Marquis said after the game. "I tried to do my part ... Ubaldo was just sharp tonight. You just tip your hat, and it's one of those games."
Astros manager Brad Mills said Sunday he'd like to limit Lyles to about 165 or 170 innings this season. Lyles has thrown a combined 106 innings between Triple-A Oklahoma City and the Astros.
"Getting up to near 165, 170 is what we kind of thought about," Mills said. "We might go over that a little bit, depending on where he's at. Those are some pretty good numbers. If he reaches that, we really need to take a look at it. You're looking at a 15-20 [innings] increase [over 2010]."
Nationals: Hairston Jr. set to return
Utility man Jerry Hairston Jr. is expected to join the Nationals on Monday and be activated from the disabled list.
Hairston, who has been on the DL since July 1 because of a fractured right wrist, just completed his rehab assignment with Double-A Harrisburg.
In two games with Harrisburg, Hairston was 1-for-6 with an RBI. On the season, the 25-year-old is batting .260 with two homers and 17 RBIs in 69 games.
Danny Espinosa leads all big league second basemen with 17 homers.
Reliever Ryan Mattheus, who took the loss on Sunday, has given up one run in eight innings during eight July appearances.
Astros: Bourgeois continues rehab
Jason Bourgeois went 2-for-5 with a run scored and a stolen base for Double-A Corpus Christi on Saturday night.
He started in center field during his fourth rehab game overall, his first with the Hooks, and is 5-for-15 (.333) during that span.
Bourgeois has been on the DL since June 29 because of a strained right quad.
Jeff Keppinger has struck out just six times in 166 plate appearances this season, which ranks first in the Majors.
Including Sunday, Fernando Rodriguez has not allowed an earned run in 14 of his 18 big league outings.
Lyles will face the Nationals for the first time in his career.
Marquis is 9-8 with a 5.50 ERA lifetime against the Astros, in 29 games (24 starts).