According to Nikkan Sports, the Seibu Lions are looking for offense and could be interested in twenty-eight-year-old Ernesto Mejia.
In terms of where he would play, he could spend time at both first base and designated hitter, since Takeya Nakamura is still recovering from back tightness. There may be more options if he can, or is willing to, play the outfield (he does have some limited experience). But more than defense, the Lions may be attracted to the righty's offensive potential -- if he can hit in the middle of the order, he would extend the line-up and help take pressure off Nakamura.
Source: Nikkan Sports 4/26/2014
[UPDATE 4/27 @ 7:40pm]
The Braves have released Mejia so that he can sign with Seibu. From MLB.com:
Despite producing good power numbers over the past few seasons in the Braves' Minor League system, Ernesto Mejia has not been widely viewed a Major League-caliber player. But Mejia will have a chance to make some money and improve his stock as he spends the rest of this year playing for Japan's Seibu Lions.
The Braves released Mejia from their 40-man roster on Saturday to allow him the chance to sign with Seibu. Specifics of Mejia's contract and the financial return the Braves will receive were not revealed.
Source: MLB.com 4/26/2014 via Sanspo 4/27/2014