The Red Sox took the first step toward shoring up their embattled bullpen Friday, acquiring left-handed reliever Matt Thornton from the White Sox.

Thornton fills a serious need for the Red Sox, as Andrew Miller‘s injury last week left Craig Breslow as the only southpaw remaining in the Boston bullpen.

Miller, whose impending foot surgery will likely put him out for the remainder of the season, was placed on the 60-day disabled list to make room for the new acquisition.

Thornton, 36, has appeared in 40 games for the White Sox this season, posting a 3.86 ERA and 1.25 WHIP. He has spent eight of his 10 major league seasons in Chicago, earning an All-Star bid in 2010.

In exchange for Thornton and cash, Boston will send minor league outfielder Brandon Jacobs to Chicago.