Red Sox acquire lefty Matt Thornton

OAKLAND, Calif. -- The Boston Red Sox, acting swiftly after losing Andrew Miller to a season-ending foot injury, announced Friday night that they have acquired left-handed reliever Matt Thornton and cash from the Chicago White Sox for minor-league outfielder Brandon Jacobs.

"You don't go into July hoping to trade for a reliever,'' Red Sox general manager Ben Cherington said in a conference call Friday night. "But we are what we are. We've had a lot of attrition in that area, and when Andrew went down, that probably increased our urgency.''

Thornton, in Philadelphia with the White Sox on Friday night [the game was rained out], is expected to join the Red Sox in time for their game against the Athletics on Saturday night.

Another reason the Red Sox acted now instead of waiting closer to the July 31 trade deadline, Cherington said, is because of the team's schedule immediately after the All-Star break. The Red Sox open with a seven-game homestand against division rivals New York [three games] and Tampa Bay [four], then follow those with a three-game visit to Baltimore.

Cherington said Thornton has had success against left-handed hitters in the AL East: Since the start of the 2010 season, left-handed hitters for Boston's AL East rivals are a combined 13-for-69 (.188) against Thornton, with one home run [Travis Hafner of the Yankees].

"He's a guy with a track record from the left side,'' Cherington said. "It's also about the rest of the [bullpen] group, trying not to put too much of a load on them.''

Thornton, 36, is a fastball-slider pitcher whose velocity still averages more than 94 mph, though his strikeout ratio has dropped each year from 12.02 per nine innings to 6.75 this season. He has made 40 appearances [28 innings] this season for the White Sox and has held left-handed hitters to a .173 average (9-for-52), though three of the four home runs he has given up have been to left-handed hitters.

Right-handed hitters have knocked him around, with a slash line of .320/.414/.420. But the veteran Thornton, who has an 0-3 record and a 3.86 ERA [his highest ERA since 2007], gives Boston a veteran arm to pair with Craig Breslow in the absence of Miller, who was enjoying the best season of his career until he tore a ligament in his left foot while backing up home plate last Saturday night against the Angels in Anaheim, Calif.

"He's not 29 anymore,'' Cherington said. "He used to have elite, elite stuff. Now it may be really good stuff, but we're confident he still has plenty of stuff to get people out.''

The Red Sox had a scout present in Detroit on Thursday when Thornton last pitched. He touched 97 mph, Cherington said, in a scoreless inning.

Thornton is in the last year of a two-year, $12 million contract extension. There is also a club option for 2014 for $6 million. A Red Sox source said the club received $750,000 from the White Sox along with Thornton, almost enough to pay his $1 million buyout if the club does not exercise the 2014 option.

Cherington said the club would wait until after the season before deciding whether to exercise Thornton's option.

The trade of Jacobs comes one day after the 22-year-old outfielder was promoted from Class A Salem, where he was in his second season, to Double-A Portland.

Jacobs, a 10th-round draft pick in 2009 who was given a big bonus ($750,000) to induce him to break a football commitment to Auburn, was hitting a modest .244/.334/.440 overall at Salem, but had turned it on in the 11 games before his promotion, batting .410/.510/.718 with two home runs and six doubles. Jacobs had two hits, including a triple, in his Double-A debut on Thursday and had one hit in two at-bats before being pulled mid-game on Friday.