The Devil Rays submitted a winning bid of about $4.5 million to the Yakult Swallows, well below the $51 million the Boston Red Sox paid to the Seibu Lions this week to negotiate with pitcher Daisuke Matsuzaka.
The Devil Rays will have 30 days to reach a contract with Iwamura. If a deal cannot be reached the Swallows will return the posting fee and Iwamura will have to wait a year to restart the process.
A five-times all-star and six-times Gold Glove winner, Iwamura helped lead Japan to victory at the inaugural World Baseball Classic.
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In eight seasons with the Swallows, the slugging third baseman has hit 188 homers and 570 RBIs.
Iwamura holds the Yakult record for most homers by a Japanese native with 44 and has hit 30 or more home runs in each of the last three seasons.
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