The Diamondbacks seek to end their struggles against the Giants in a four-game series at AT&T Park that begins Thursday night.
Arizona (70-68) trails Cincinnati by seven games for the NL's final wild-card spot after rallying for a 4-3 win in 10 innings Wednesday against Toronto. Willie Bloomquist's third hit of the day helped the Diamondbacks avoid an interleague sweep.
Arizona, losers in five of seven, will next try to improve on its meager 5-10 record against San Francisco. The Diamondbacks dropped two of three to the Giants (62-77) this past weekend.
Arizona's Trevor Cahill (5-10, 4.39 ERA) and San Francisco's Ryan Vogelsong (3-4, 5.49) matched up in the middle game of that set, and will be the starters for Thursday's opener.
Cahill kept San Francisco scoreless for the first six innings Saturday before giving up three runs in the seventh. Eric Chavez secured Arizona's lone win in the series with an RBI single in the ninth.
Cahill is 2-0 with a 3.22 ERA in four starts since coming off the disabled list and has a 2.08 ERA in his last three.
"I think he ran out of gas a little bit right there. You saw a lot more pitches were in the dirt in that last inning than the rest of the game, but we had to extend him as far as we could," manager Kirk Gibson told the team's website.
Vogelsong allowed all three of his runs in that 4-3 loss in the fourth of his six innings. The right-hander is 1-0 with a 2.93 ERA in five outings since returning from an 11-week stint on the DL for a fractured hand.
"In that one inning, I got a little loose mechanically and that had an effect on how sharp the pitches were," Vogelsong said. "The rest of the game wasn't too bad."
Cahill has given up three runs or fewer in two of his three starts against San Francisco this season. He was tagged for a season-high eight runs over 3 2-3 innings in the other matchup, a 10-5 loss June 8.
Bloomquist will try to help the right-hander by adding to .571 average (12 for 21) since returning from a bruised left hand. He went 5 for 10 in last weekend's series and got a pair of singles off Vogelsong.
Aaron Hill is 7 for 14 with a home run all-time against Vogelsong and Gerardo Parra is 3 for 6 this season.
Angel Pagan, seeking a 10-game hit streak, is 3 for 7 this season against Cahill and 7 for 15 over his career. Pablo Sandoval is 6 for 20 all-time versus Cahill and enters this series hitting .389 with 19 RBIs in his last 19 games.
Sandoval had three homers and drove in a career-high six runs in a 13-5 rout of San Diego on Wednesday, helping San Francisco avoid a three-game sweep.
Buster Posey, who is 8 for 16 in his last four games, could return Thursday from an ailing finger.