The San Francisco Giants, badly struggling for offense, have acquired Philadelphia Phillies outfielder Hunter Pence, a high-ranking Phillies official with direct knowledge of the trade confirmed to USA TODAY Sports. The executive spoke on condition of anonymity because the deal is not yet official.

Pence, who is eligible for free agency after 2013, is hitting .271 with 17 homers and 59 RBI this season.

In return, the Phillies will receive outfielder Nate Schierholtz, Class AA catcher Tommy Joseph (generally rated the Giants' No. 2 prospect before this season) and minor league pitcher Seth Rosin.

The move comes on the heels of the Phillies' trade of Shane Victorino to the Dodgers, a rapid response to what's quickly becoming an arms race in a taut National League West race.

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"Everything is understood," Pence said of the trade. "The Phillies are going in a different direction. We had a great run at it. Now I'm going a different way."

Pence is making $10.4 million this season and figures to be due a significant raise via arbitration next season. His acquistion marks the second consecutive year the Giants have gone after an outfielder in an effort to make the playoffs. They dealt top pitching prospect Zack Wheeler to the New York Mets for Carlos Beltran in 2011.

However, the Giants failed to make the playoffs after that deal.

The Giants, who have the National League's 11th-best offense, needed outfield help with the recent decline of right fielder Gregor Blanco, who has a mere .553 OPS [on-base plus slugging percentage] in July. Pence, hitting .271 with 17 homers and 59 RBI this season, will replace him in right field.

Pence's trade shifts the Phillies' sell-off into a higher gear. They are expected to recall outfielder Domonic Brown before tonight's game to replace Victorino, and will field an outfield of Juan Pierre, John Mayberry and Brown - assuming Pierre isn't dealt, either.

The Phillies begin Tuesday's games 13 games out in the NL wild-card race, and 16 1/2 games behind Washington in the NL East.

Contributing: AP