MLB

Red Sox send Lester to A’s in monster swap for Cespedes

Red Sox ace Jon Lester is headed to the Oakland A’s in exchange for outfielder Yoenis Cespedes, according to The Post’s Joel Sherman.

Outfielder Jonny Gomes also is going to the A’s to take over left field from the 28-year-old Cuban slugger Cespedes, who is batting .256 with 17 homers in the third year of a four-year, $36 million contract.

It’s the latest going-for-broke move from Oakland general manager Billy Beane, who earlier this month dealt top prospect Addison Russell to the Cubs in a package for right-handers Jeff Samardzija and Jason Hammel.

Lester is eligible to become a free agent after this season, and it is possible he could re-sign with the Red Sox over the winter as they reload for 2015.

In recent days, as the last-place Red Sox acknowledged their hopeless place in the standings, the 30-year-old Lester was linked with the Mariners and a host of National League clubs, including the Dodgers, Cardinals, Pirates and Brewers.

The lefty is about as proven a postseason starter as they come. He has a 2.11 ERA in 76 2/3 playoff innings, including a microscopic 0.43 ERA in three World Series starts en route to two rings.

The A’s, who own an MLB-best 66-41 mark, now can boast a playoff rotation of Lester, Sonny Gray, Scott Kazmir and Samardzija.

Oakland made another move to add outfield depth, acquiring Sam Fuld — who played seven games with the A’s early in the season — from the Twins in exchange for right-hander Tommy Milone.