The Athletics have acquired Alberto Callaspo from the Angels, according to Ken Rosenthal of FOX Sports (on Twitter). Danny Knobler of CBS Sports tweets that the A's will send Grant Green to the Angels in the deal, which has now been officially announced.

Callaspo, 30, was hitting .253/.323/.348 with five homers for the Angels so far this season, prior to tonight's game. Originally acquired from the Royals, he has extensive experience at second and third base, though he hasn't played second base since 2010. In spite of that fact, the A's plan to use him at second, according to MLB.com's Jane Lee (Twitter link). He is under contract for the 2014 season at $4.875MM — the second year of a two-year deal he signed with Anaheim this offseason.

The Athletics selected Green, 25, with the 13th overall pick inthe 2009 draft. He's 0-for-15 with the A's thus far in 2013 — his first taste of Major League action, but he's batted .325/.379/.500 with 11 homers in 415 plate appearances at Triple-A this season. He ranked among the game's Top 100 prospects from 2010-11 according to Baseball America and in 2012, according to MLB.com.

Prior to the 2013 season, BA ranked Green eighth among A's prospects, noting that he may not be an impact bat but should provide enough offense from second base to be a solid regular. MLB.com's Jonathan Mayo ranked Green as the No. 3 prospect in Oakland's system, noting that he could be an offensive-minded second baseman who has plus athleticism.

Photo courtesy of USA Today Sports Images.