Oakland A's trade Ryan Cook to Boston Red Sox for player to be named later

The Oakland Athletics traded 2012 All-Star right-handed relief pitcher Ryan Cook to the Boston Red Sox for a player to be named later, reports Jon Heyman of CBS Sports and the Bay Area News Group's John Hickey. There is no word yet on the return. Cook, 28, got off to a terrible start and never returned to form to merit a return to the club despite Oakland's bullpen woes.

Oakland Clubhouse's Melissa Lockard has one guess as to who the player to be named later might be:

Total speculation based on nothing but my guess, but perhaps the PTBNL is Daniel Nava, currently on release waivers.

— Melissa Lockard (@oakclubhouse) July 31, 2015

Cook made just four appearances and conceded five earned runs before getting demoted to Triple-A Nashville. In Nashville, Cook could not manage a performance that suggested success in the major leagues, striking out 26 but walking 14 in 33⅓ innings, resulting in a 4.05 ERA.

The Red Sox see Cook as a bounceback candidate, however, says Brian Macpherson of the Providence Journal:

Farrell: Red Sox liked Ryan Cook's track record, see him as a "bounce back" candidate this year and beyond.

— Brian MacPherson (@brianmacp) July 31, 2015

Cook has a career 2.93 ERA and has one option year remaining after this season. With just over three years service time, he is under Red Sox control through at least the 2018 season.