Source: Padres send Kouzmanoff to A's

After coming up short in a bid to sign free agent Adrian Beltre, the Oakland Athletics filled their third base void Friday by acquiring Kevin Kouzmanoff in a four-player trade with the San Diego Padres, a baseball source confirmed.

Kouzmanoff, who hit 18 homers and drove in 88 runs for San Diego in 2009, goes to Oakland with a minor leaguer in exchange for outfielders Scott Hairston and Aaron Cunningham, the source said.

MLBTradeRumors.com and the San Francisco Chronicle were first to report the deal. The players involved must pass physical exams before the trade becomes official.

Acquiring Kouzmanoff will help with Oakland's efforts to upgrade defensively this offseason. Kouzmanoff made only three errors in 311 total chances at third base last year for a .990 fielding percentage, breaking the previous National League third base record of .987 set by Colorado's Vinny Castilla in 2004. Kouzmanoff sent a glove to the Hall of Fame after the season at the museum's request.

In December, the A's signed free agent center fielder Coco Crisp, also considered a top defender, to a one-year, $5.25 million contract.

With the departure of Kouzmanoff to Oakland, Chase Headley is expected to move from left field to third base in San Diego. Hairston and Cunningham bring depth to a San Diego outfield that currently consists of Will Venable, Tony Gwynn Jr. and Kyle Blanks.

Cunningham, a sixth round draft pick by the Chicago White Sox in 2005, has been traded three times since 2007. He's a .211 hitter in 133 major league at-bats with Oakland, but hit .302 with a .479 slugging percentage for the A's Triple-A Sacramento farm club last season.

Cunningham recently underwent surgery for a sports hernia, but the injury is not considered serious. Cunningham told ESPN.com that he's scheduled to undergo a physical exam Saturday in conjunction with the trade.

"I'm really excited,'' Cunningham said. "I've always told my wife that San Diego is the place where I want to finish my career.''

Jerry Crasnick covers baseball for ESPN Insider.