CHICAGO (AP) -- Theo Epstein was the first person to take a chance on Felix Doubront. Now he is going to give the struggling left-hander another opportunity.
The Chicago Cubs acquired Doubront from the Boston Red Sox on Wednesday in exchange for a player to be named. Epstein, the president of baseball operations for the Cubs, was Boston's general manager when Doubront signed with the Red Sox as an undrafted free agent in 2005.
Cubs manager Rick Renteria said he didn't know very much about Doubront, and the team said it would announce in the next couple days where he would begin with the organization. Doubront pitched against the Cubs on July 2, allowing three runs and four hits in 1 1-3 innings of relief.
''I reserve my right to come to my own judgment on what he's about,'' Renteria said.
The 26-year-old Doubront had grown unhappy with his role in Boston. He was shuttled to the bullpen during the playoffs last year, when the Red Sox won the World Series for the third time in 10 seasons. He made four appearances in the postseason, allowing one run in seven innings.
He was again bumped from the rotation this season - and again expressed his displeasure. But Doubront did little to pitch himself back into a starting role. He recorded just two outs in his final appearance with Boston on Monday, allowing six runs in mop-up duty in a 14-1 loss to Toronto.
As the defending World Series champions fell further into last place in the AL East, it became obvious they had little use for a disgruntled and ineffective reliever.
Doubront won 11 games in each of the previous two seasons. He struck out 167 in 161 innings in 2012. But he was 2-4 with a 6.07 ERA in 17 games, 10 starts, with the Red Sox this year.
The trade is Epstein's fourth deal with his former team since he took over the Cubs in October 2011.
It could be the start of a busy week for the plummeting Red Sox, who have conceded their title defense after losing eight of their last nine games. Starters Jon Lester and John Lackey are also on the trading block.
The Cubs also could be active ahead of Thursday's non-waiver trade deadline. Utilityman Emilio Bonifacio did not play in Wednesday night's 10-inning loss to Colorado, with Renteria acknowledging the trade talk surrounding the speedy switch hitter.
''I'm just waiting for whatever is going to happen,'' said Bonifacio, who is batting.400 (14 for 35) in his last eight games.
Also Wednesday, Chicago completed this week's trade with Los Angeles when it received minor league pitcher Jonathan Martinez from the Dodgers. The Cubs sent second baseman Darwin Barney to the NL West leaders on Monday.
Martinez, a 20-year-old right-hander, was 7-5 with a 3.47 ERA in 19 starts for Class A Great Lakes this season. He was signed by the Dodgers as a non-drafted free agent in May 2011 out of Venezuela.
The Cubs also recalled left-hander Chris Rusin from Triple-A Iowa and sent right-hander Blake Parker to their top farm club. Parker pitched two innings as the Cubs used eight relievers in Tuesday night's 4-3 victory over Colorado in 16 innings.
AP Sports Writer Jimmy Golen in Boston contributed to this report.
Jay Cohen can be reached at http://www.twitter.com/jcohenap