"He's obviously been successful," said Red Sox general manager Ben Cherington. "He hit a little speed bump this year, but we continue to want to try to take a look at guys in looking forward and trying to find solutions for the pitching staff. Ryan will join us here at some point."
Boston made a similar move earlier this week, claiming righty Jean Machi off waivers from the Giants.
"Well, he's a guy who has been a closer in the past," said Red Sox manager John Farrell of Cook. "I know that there's been some change of role for him out in Oakland. And as we did with Jean Machi, he'll come in and we can take a look at him. This will be a very similar situation."
Cook was an upper-echelon reliever while making 142 appearances for the A's in 2012-13.
Hanley, Sandoval nursing injuries
Hanley Ramirez and Pablo Sandoval, both injured in Thursday's game against the White Sox, were out of the Red Sox's starting lineup for Friday's series opener against the Rays. Both players are day to day, but Farrell said he expects Ramirez to be back in the lineup for Saturday's game.
Ramirez fouled two balls of his shin in the fifth inning, but managed to stay in for the rest of the contest. After the game, his shin continued to tighten up. Sandoval was struck on the left forearm by a pitch from Chris Sale that he swung through in the fourth inning. He hunched over immediately after being hit, but X-rays after the game showed just a contusion.
"Pablo is sore and still has some swelling in his left wrist, forearm area. He won't be swinging the bat today," Farrell said. "Depending on the coming day or days and if there is no significant improvement, we would then consider more tests."
Ian Browne is a reporter for MLB.com. Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.