The two teams couldn't be having more different seasons, as the Giants own the division lead in the National League West while the rebuilding Astros are attempting to finish the second half on a positive note.
For the Giants, they'll need Zito to ensure a victory against the team with the league's worst record, especially with the Dodgers making bold moves in an attempt to gain ground in the division.
Zito is enjoying a solid season. He followed two subpar outings by going eight-plus innings nd allowing two runs to the Braves -- although those two runs were the result of runners he left on base before exiting.
"It feels good to help the team," said Zito after picking up the win. "It's great momentum-wise to go out there and help the team get back on track."
Zito is 9-1 when the Giants support him with four runs or more, so he'll hope his team can back him against Keuchel. The Houston lefty had posted three straight quality starts. However, he gave up five runs in four-plus innings to St. Louis in his last outing.
Even with the Dodgers acquiring Adrian Gonzalez and Josh Beckett, and the Giants being without what was one of their top hitters in Melky Cabrera, San Francisco has managed to increase its division lead. The club is 8-4 without Cabrera and 3 1/2 games ahead of Los Angeles.
Giants: Mota back from suspension
Right-hander Guillermo Mota returned from a 100-game suspension issued on May 7 after he tested positive for a banned substance. Mota said he doubted he would be brought back, especially after the Cabrera suspension, however manager Bruce Bochy said he paid his price.
"Everybody makes mistakes," Bochy said. "I do, you do, and unfortunately we all do. And when we do, there are consequences. He paid the consequences with a pretty good suspension."
The 39-year-old Mota will add depth to the Giants bullpen, Bochy said.
Bochy also said that first baseman Aubrey Huff is likely to be reinstated from the disabled list after rosters expand Saturday. Huff last appeared for the Giants on June 10 and is hitting .155. He suffered a sprained right knee on June 13.
Astros: Lowrie progressing, hopes to play this year
One bat the Astros didn't trade away was that of shortstop Jed Lowrie. Lowrie, though, has been on the disabled list since July 15 with a nerve injury in his right knee. Lowrie hopes to return in the next two or three weeks.
"I'll just continue to take each step, jump through every hoop and make sure it's good to go and get back out there as soon as possible," Lowrie said.
Tony DeFrancesco has been managing the team on an interim basis since Brad Mills was let go on Aug. 18. However, the search for a permanent manager continues, general manager Jeff Luhnow said.
"We're continuing to assess our list of candidates," Luhnow said.
It's been a rough second half for the Astros. The club is 7-36 since the All-Star break and previously set a club record with 12 straight losses. They enter Wednesday having lost 10 of their last 11 and are 1-6 against the Giants.