A’s to deal Harden to Red Sox

Surprisingly quiet for much of the week, the A’s finally entered play in a bustling trade scene Saturday, closing in on a deal that will send right-hander Rich Harden to the Red Sox, a Major League source confirmed.

The deal is not yet considered done, but the A’s are expected to receive first base prospect Lars Anderson and a player to be named later in return.

Harden’s second tour of duty in Oakland marked a short reunion, as the 29-year-old righty made just five starts for the club — going 2-1 with a 4.30 ERA — after signing a one-year deal worth $1.25 million only to suffer a strain to his lat muscle in mid-February that kept him away from a big league mound until July 1.

Harden offers pitching depth to a Red Sox team that was tirelessly working on adding a starter to the mix by Sunday’s 1 p.m. PST non-waiver Trade Deadline.

Anderson, an Oakland native, was a 2006 18th-round Draft pick by the Red Sox out of Jesuit High School in Sacramento. He’s batting .261 with 10 home runs and 57 RBIs, along with 59 walks and 92 strikeouts, for Triple-A Pawtucket.

The 23-year-old made his Major League debut in 2010 and at one time was considered Boston’s first baseman of the future. But those plans changed upon the offseason arrival of Adrian Gonzalez, who was signed to a seven-year extension.

Anderson could offer the A’s immediate help at the big league level in an already youthful infield, as the club is without a true first baseman following Daric Barton’s demotion to Triple-A Sacramento in June. Barton, who hit just .212 with no home runs and a .592 OPS in 67 games for the A’s, was recently diagnosed with a torn labrum in his right shoulder and is expected to miss the rest of the season.

Harden was next scheduled to start for the A’s in Seattle on Tuesday, but Oakland has several replacement options, including right-handers Tyson Ross and Graham Godfrey and lefty Josh Outman.

– Jane Lee