The St. Louis Cardinals just avoided falling below .500 for the first time this season.
Giving Lance Lynn his usual run support would likely prevent the Cardinals from leaving Houston back at the break-even point.
Lynn gets a second chance to win his ninth game of the season Thursday night when the Cardinals and Astros conclude their three-game set.
After having lost six of seven, including a 9-8 defeat in Tuesday's series opener, the Cardinals (29-28) posted a 4-3 victory Wednesday to improve to 3-6 on a trip that ends Friday.
St. Louis had dropped 11 of 13 away from home.
The Cardinals will try to head into a 15-game stretch of interleague play on a positive note by giving Lynn (8-2, 2.63 ERA) the ball in Houston for the first time since he threw five innings of one-run ball and won his first career game there last June 9.
The right-hander, though, will take the hill at Minute Maid Park on the heels of a rough outing in Saturday's 5-0 loss to the New York Mets. Lynn walked a season high-tying four and yielded three runs in 4 2-3 innings.
"I have to pitch better than that," he told the Cardinals' official website after failing to make it out of the fifth for the first time in 2012.
The Cardinals - the NL's second-highest scoring team at 5.05 runs per game - had scored at least four times in each of Lynn's first eight outings of 2012. His run-support average is a league-best 6.98.
The Astros (24-32) will counter with J.A. Happ (4-5, 4.31), who has not had the luxury of pitching with a cushion lately. The left-hander has lost his last two starts, with Houston scoring once in each outing.
"I think Happ gave us exactly what we needed tonight,'' manager Brad Mills said after Happ gave up three runs and struck out seven in Friday's 4-1 loss to Cincinnati. "He got us through (a season-high) seven innings. It was a quality start. I know it was a losing effort, but it was a quality start."
It's been a while since he's done that in this series. Since throwing a two-hitter Aug. 30, 2010, Happ has a 7.62 ERA while losing his last five starts against the Cardinals. He walked four and gave up a season-high six runs in an 8-1 home loss to St. Louis on May 6.
Happ should be especially careful with Allen Craig, who is 5 for 7 with two homers against him. Craig is a career .415 hitter off Astros pitching after going 4 for 9 with a homer in the first two games of this series.
Astros second baseman Jose Altuve has raised his career batting average against St. Louis to .438 (21 for 48) by going 6 for 10 in the last two games.
He has never faced Lynn.
Neither has center fielder Jordan Schafer, who could play Thursday after being out of Houston's starting lineup the last two games with an illness. He was a pinch runner in the ninth inning Wednesday.
Happ was a pinch runner the inning before after Marwin Gonzalez suffered a bruised right heel when tripping on first base following his bunt single.