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(SportsNetwork.com) - The San Francisco Giants continue their push toward the postseason on Tuesday when they open a three-game set with the Arizona Diamondbacks at AT&T Park.

San Francisco enters the tilt holding one of the two wild card spots in the National League, but also trails the NL West-leading Los Angeles Dodgers by 3 1/2 games.

The Dodgers will pay a visit to San Francisco this coming weekend for a three- game set.

San Francisco took two of three from the Detroit Tigers this past weekend, but was denied a sweep on Sunday with a 6-1 loss at Comerica Park. It was just the third loss for the Giants in the last 12 games.

Hoping to get the Giants back in the win column on Tuesday will be righty Yusmeiro Petit, who is 4-3 with a 3.89 ERA. Petit was awful in Colorado on Tuesday, as he served up six runs and seven hits in four innings of a 12-7 win.

Petit spent three seasons -- 2007-09 -- in Arizona before reviving his career with the Giants. He's 2-1 lifetime against the D-backs with a 2.57 ERA in six games (2 starts).

Arizona, meanwhile, will counter with lefty Wade Miley, who is winless in his last six starts (0-3). Miley did not get a decision on Tuesday in San Diego, but pitched well, giving up a run and seven hits in seven innings of his team's 2-1 loss.

Although he is 0-2 in his last four starts, his ERA is only 1.69 in that stretch, and he is averaging close to one strikeout per inning.

"I felt pretty good," said Miley, who is 7-10 with a 4.18 ERA on the year. "Even in the bullpen, I felt like I was going to be able to get ahead of guys, and that's key. ... I was fortunate that they hit balls at people."

Arizona continues to play out the string and was swept over the weekend by the Dodgers, culminating with a 7-2 setback on Sunday. Cody Ross collected three of Arizona's six hits, including an RBI single.

The Diamondbacks have lost 12 of their last 14 road games.

San Francisco is 8-5 this season against Arizona.