Rookie left-hander Brett Oberholtzer has done nothing but impress since moving to the Astros' starting rotation late last month.
In three career starts, he is 2-1 with an 0.87 ERA, allowing two runs on 14 hits in 20 2/3 innings.
He'll look to keep those numbers going on Sunday as the Astros and Angels square off in the series finale at Angel Stadium. Houston has six victories in Anaheim this season of its 21 total road wins.
Oberholtzer took a loss on Monday to the Rangers after allowing just two runs on seven hits in 6 2/3 innings. He also struck out six and walked two.
"I'm a guy that likes to settle in," Oberholtzer said after the start. "They got to me early, but other than that, I felt pretty good. Body-wise, not quite the same [as his first two starts], but some days, you'll wake up and not feel 100 percent."
Jason Vargas will be on the hill for the Angels, marking his second start since returning from the disabled list with a blood clot.
Making his first start in close to two months against the Yankees on Tuesday, the left-hander gave up four runs on eight hits in 4 1/3 innings for the loss. While he had a lead in the game, Vargas' undoing came in the fifth when he surrendered a two-run home run to Alfonso Soriano.
In one start against the Astros earlier this season, Vargas allowed five runs on 10 hits in 5 2/3 innings for a no-decision. He also struck out seven and walked two.
Astros: Fields, Lo to share closer's role
• The closing duties have been narrowed to rookies Josh Fields and Chia-Jen Lo, manager Bo Porter said on Saturday.
Porter had been employing a closer-by-committee approach since the team traded Jose Veras to the Tigers on July 29.
Fields took the loss on Saturday when he surrendered a game-winning home run to Josh Hamilton in the 10th inning. Lo threw a scoreless ninth inning Friday to become the first Astros pitcher in 10 years to begin his career by making seven scoreless appearances.
"I'll fluctuate between Fields and Lo based on the workload previously leading up to that," Porter said. "It's a good option to have both of those guys pitching well."
Angels: Green settling in with Halos
• While Grant Green began his Major League career going 0-for-15, the infielder has turned things around since then.
Green is hitting .382 (13-for-34) since joining the Angels, has hits in seven of his past 11 games and already has notched five multi-hit games.
"I'm just more comfortable," Green said. "I don't feel like I'm in a groove where the ball looks like a beach ball in a sense, but at the same time, I'm getting more ABs and being able to settle into a new organization and being able to settle in to hitting in the big leagues."
• While Howie Kendrick's strained left knee continues to progress, the Angels aren't putting a timetable on when the second baseman will return.
• When the Astros score first, they are 24-30 this season.
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.