Zito again will try for his first National League win as the Giants (3-7) continue their weekend series against the Pittsburgh Pirates on Saturday.
The left-hander went 102-63 with a 3.55 ERA pitching with the Oakland Athletics from 2000-06 and was highly sought in free agency before signing a seven-year deal and the richest contract ever for a pitcher on Jan. 2.
In his first two NL starts, though, Zito (0-2, 8.18 ERA) has struggled and is coming off one of the worst outings of his career. He lasted six innings in the Giants' 10-4 loss to the Los Angeles Dodgers on Sunday, but was tagged for eight runs and nine hits as opponents increased their batting average against him to .295.
San Francisco, meanwhile, is hitting just .239 when Zito pitches.
"You've got to focus on doing your job and keeping the team in the game," Zito told the Giants' official Web site. "If you start to take on the burdens of the offense ... it's not going to go as planned."
But Zito could be in line for a win if Barry Bonds continues to hit well against the team he broke into the major leagues with more than two decades ago. The seven-time NL MVP was 3-for-3 with two homers -- leaving him 18 shy of tying Hank Aaron's all-time record -- as the Giants won 8-5 on Friday night.
Bonds was hitting just .192 with one homer coming into this series before singling home Omar Vizquel during a five-run first inning. He then hit a two-run homer in the second off starter Zach Duke and added a solo shot in the fourth off Shawn Chacon to make it 8-2 before being lifted.
Bonds has hit 96 of his 737 homers in Pittsburgh, but just seven in PNC Park since it opened in 2001.
"What a day he had," said Giants manager Bruce Bochy, whose team scored only 20 runs in its first nine games. "We've been trying to get this offense going and that's what we needed."
With 70 career multihomer games, Bonds also is two behind Babe Ruth's major league record of 72.
Tony Armas (0-1, 13.50) will make his home debut for the Pirates. In his first start last Saturday with Pittsburgh after spending 1999-2006 with the Montreal-Washington franchise, Armas gave up six runs, eight hits and walked five over four innings of a 7-5 loss in Cincinnati.
"He did have some deep counts, evident by the fact that he threw close to 90 pitches or something like that through four innings," said Pirates manager Jim Tracy, who needs two wins for 500 in his career. "That right there gives you some idea that there weren't too many quick outs."
While with the Nationals, Armas lost his only start versus the Giants in 2006, when he yielded six runs and eight hits in 3 2-3 innings of an 8-6 defeat on Aug. 2 in San Francisco. Overall, the right-hander is 1-4 with a 5.28 ERA in five starts against the Giants.