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The struggling San Francisco Giants will try to win for just the second time in six games when they open a three-game series against the visiting Chicago Cubs on Friday.

San Francisco hopes tonight's starter Matt Cain can help get the club back in the win column, and his career numbers against the Cubs suggest he has a good chance of playing a stopper role in the opener of this series.

The Giants have lost four of their last five games and the defending World Series champions are now seven games out of first place in the NL West. The club has surrendered a total of 34 runs during the recent five-game stretch, which included losses in three out of four games against the visiting Cincinnati Reds.

San Francisco was dealt an 8-3 loss by the Reds on Wednesday and that actually was the closest losing margin during the series. Cincinnati also posted victories of 11-0 and 9-3 during its stay at AT&T Park, while the Giants managed a 5-3 win in its lone victory of the set.

The Giants lost Wednesday's finale despite out-hitting the Reds by a 15-13 margin. Hunter Pence went 5-for-5 with an RBI and Pablo Sandoval had two hits and drove in a pair of runs for the Giants, who left 15 runners on the basepaths.

"Disappointing tonight. We squandered too many chances tonight. It doesn't matter how many hits you get, it is when you get them," said Giants manager Bruce Bochy.

Chad Gaudin (4-2) was tagged for six runs on seven hits and five walks over 3 2/3 innings to absorb the loss for San Fran.

Although Cain has struggled mightily this season, sporting a 6-6 record and 5.00 earned run average through 20 starts, the right-hander has had success against the Cubs over the years.

Cain is 6-2 with a 2.46 ERA in 14 career starts versus the Cubs and his knack for baffling the club was evident when he last faced Chicago back in April. Cain yielded two runs over seven innings on April 12, but he wound up with a no-decision in his team's 4-3 loss.

Although he was hardly efficient in his first start following the All-Star break, Cain was able to pick up a win Saturday against Arizona. He surrendered just two runs and four hits, but also walked four batters and was lifted after throwing 102 pitches in five innings.

The Cubs, who are 17 1/2 games out of first place in the NL Central, have reportedly traded outfielder Alfonso Soriano to the New York Yankees. The 37- year-old Soriano spent the first five seasons of his career in the Bronx before being traded to the Texas Rangers for Alex Rodriguez in 2004.

Soriano was a late scratch from Chicago's lineup on Thursday and the deal is said to be awaiting league approval. Multiple reports have suggested Soriano will be in the lineup for the Yankees tonight when they face the Tampa Bay Rays.

"I don't know what the Cubs get, but I'm happy. I think they are happy too because they get something back. I'm happy to go back to New York where I started my career," Soriano said after Thursday's game.

Without Soriano, who has 17 homers this season, the Cubs were handed a 3-1 loss Thursday in the finale of a four-game series in Arizona. Wade Miley worked 7 2/3 innings of one-run ball to guide the Diamondbacks to a 3-1 win to split the series.

Cubs starter Carlos Villanueva (2-7) allowed all three runs on six hits while striking out five over five innings. Welington Castillo went 2-for-3 with an RBI for Chicago.

The Cubs will send Edwin Jackson to the mound tonight, as the right-hander shoots for his fourth win in five starts.

Jackson is 6-11 with a lofty 5.03 ERA this season, but is 3-1 with a 2.45 ERA over his last four trips to the bump. His lone loss of that stretch came in his last outing despite Jackson surrendering four runs -- three earned -- and five hits over seven innings of work. He also struck out five batters while walking two.

The right-hander was touched for four earned runs over 5 1/3 innings in a no- decision against San Fran on April 14. All told, Jackson is 2-2 with a 5.06 ERA in six games (five starts) versus the Giants.

The Giants won three of four against the Cubs in Chicago back in April and San Francisco is 9-2 in this series since the start of the 2012 season. The Cubs have lost five straight at AT&T Park and last won in San Francisco on Aug. 30, 2011.