(CBS) The Oakland Athletics are all in this season in their push for a World Series.

In a blockbuster move on the morning of trade deadline day, the A’s sent outfielder Yoenis Cespedes to the Red Sox in return for left-hander Jon Lester, one of the biggest names on the trade market, and outfielder Jonny Gomes, according to multiple reports.

Lester was linked to a multitude of teams in trade rumors, but Oakland’s involvement comes as a surprise. The A’s already made one huge move in early July when they shipped top prospect Addison Russell off to the Cubs for right-handers Jeff Samardzija and Jason Hammel, and few expected them to make another big move.

In his best season to date, Lester is 10-7 with a 2.52 ERA. His contract expires at season’s end, and after he and the Red Sox continually failed to reach an agreement on a long-term deal, he went on the trade block.

Cespedes is hitting .256 with 17 homers, 67 RBIs and a .767 OPS this year.

The deal is certainly a gamble for the A’s on this season, as Cespedes is under contract through 2015.

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