Thornton, 36, has been one of three White Sox pitchers that the Red Sox have pursued in recent days, joining Addison Reed and Matt Lindstrom. Because of Andrew Miller's recent season-ending injury, there was a need for left-handed help in the Red Sox bullpen, so Thornton was an obvious fit.
The Braves were also interested in Thornton, according to Ken Rosenthal of FOXSports.com. Boston also has been linked to Brewers' relievers Mike Gonzalez, John Axford and Francisco Rodriguez, as well as Phillies' closer Jonathan Papelbon and Marlins' closer Steve Cishek. Because of the injuries and struggles that the Sox' bullpen has endured all season, it is too early to rule out another bullpen move for the first place team.
In 40 appearances with Chicago on the season, Thornton is 0-3 with a 3.86 ERA, 6.8 K/9, and 3.2 BB/9. He has been with the White Sox since they acquired him from the Mariners in 2006, and posted a 31-35 record and 3.28 ERA in 512 appearances. In 586 career major league appearances with the Mariners (2004-2005) and White Sox (2006-2013), Thornton is 32-41 with a 3.53 ERA in 553 innings of work.
The Red Sox will receive $750,000 in the deal and will pay Thornton about $2.5 million for the remainder of the season, according to Sean McAdam of CSNNE.com. He is a free agent after this season, and will no longer be eligible to receive a qualifying offer due to the midseason trade.
Jacobs, 22, was Boston's tenth round pick in the 2009 draft, and was promoted to Double-A Portland yesterday. In 81 games with High-A Salem on the season, the speedster has hit .244 with 11 HR, 44 RBI, and 10 steals. He projects as a left fielder at the major league level, and is widely regarded as having high power potential. Although he is a below average defensive outfielder, his offense is considered strong enough to outweigh his defensive struggles.
As MassLive.com's Evan Drellich points out, Jacobs would have been eligible for the Rule 5 Draft this winter, and the Red Sox were unlikely to protect him due to their multitude of eligible outfielders.
This move is the first of the trading season for the White Sox, who are known throughout the league to be one of the league's most aggressive sellers in advance of the trade deadline. They are shopping assets such as Reed, Lindstrom, Alex Rios, Jake Peavy, and the injured Jesse Crain.