With just four games remaining on the schedule, the Red Sox added the 38-year-old Stanton to manager Terry Francona's list of late-game options by acquiring him in exchange for Minor League right-handers Rhys Taylor and Yader Peralta.
"He's a veteran left-hander. I can't tell you if he'll be used or when," Francona said before Thursday's game. "He can throw his cutter effectively. This guy is not going to come in and pitch the ninth for us."
Stanton is not eligible for the postseason roster, but he would be available should the Red Sox be involved in a one-game playoff on Monday.
"I've never been a part of this," said Francona, when asked if he could remember such a late deal. "I was with the Phillies. We were sending guys to Instructional League [at this point in the season]. This is highly unusual."
Stanton begins his second stint with the Red Sox. He played for Boston for parts of the 1995 and '96 seasons. The Red Sox are in need of a left-handed reliever for an important three-game series against the Yankees this weekend.
"We came across the opportunity to add a pitcher at a very low acquisition cost for these last four games, maybe five games," Red Sox general manager Theo Epstein said. "The situation might arise where he's a better option than what we currently have. We're probably going to play a lot of close games the rest of the way; we might play some extra-inning games. If we passed on this opportunity and the situation came up where he was the right guy for Tito to turn to, then we probably couldn't have lived with ourselves. So we decided to go ahead and do it. [We] hope he can help us in a spot in the next four days."
"I was pretty surprised by the trade," said Stanton, who is a free agent after the season. "I found out on Wednesday that something was going on. I guess [the Red Sox are getting me to face the Yankees]. I'm throwing the ball pretty well, and Boston is a great place to play."
In another ironic twist, Stanton started the 2005 season with the Yankees, who released him in early July. Stanton signed with the Nationals a day after the All-Star Game. In 30 games for the Nationals, Stanton was 2-1 with a 3.58 ERA.
"We would like to thank Mike for the fine job he did not only in our bullpen, but with the knowledge and leadership he shared with our young pitchers," Washington interim general manager Jim Bowden said. "We are pleased to acquire two young pitchers with good arms."
Stanton, who lives in New Jersey, said family means a lot to him, and he would like to keep his family on the East Coast. He would consider going back to the Nationals for the 2006 season.
"I enjoyed playing for the Nationals," Stanton said. "They have some young players that could play. I'm going to leave my options open."
Taylor, 20, went 2-2 with a 1.49 ERA in 11 games (five starts) for the Red Sox's Gulf Coast League team this season in his professional debut in the United States.
Taylor signed with Boston as a non-drafted free agent after pitching last summer in the Australian Summer Baseball League. During his stint in the GCL, Taylor posted a .209 opponents' batting average and walked just 1.7 batters per nine innings.
Peralta, 19, went a combined 2-3 with four saves and a 4.57 ERA in 27 games out of the bullpen for Class A Greenville, short-season Lowell and the GCL Red Sox. In three professional seasons, Peralta has a 3.33 ERA.
Miller and Stern surgeries: Right-hander Wade Miller had successful surgery on his right labrum Thursday in Wilmington, Del. Outfielder Adam Stern had a similar surgery on his right shoulder performed by Dr. Lewis Yocum in Los Angeles.
Petagine excused: Roberto Petagine will miss the final four games of the regular season to tend to a personal situation.
"Petagine will not be here," Francona said. "He has an excused absence for a very serious matter. I'd like to leave it at that."
Arroyo available: Starting Friday, Bronson Arroyo will be available out of the bullpen for the Red Sox in their much-anticipated series against the Yankees. Arroyo threw only 79 pitches and lasted just three-plus innings in Wednesday's 7-2 loss to the Blue Jays.
Boggs honor: The Red Sox will honor 2005 Hall of Fame inductee Wade Boggs in a ceremony prior to Friday night's Red Sox-Yankees series opener at Fenway Park. Boggs, who starred for the Red Sox from 1982-92, was elected to the Hall of Fame in his first year of eligibility and was enshrined in Cooperstown on July 31.
Boggs played 18 Major League seasons with the Red Sox (1982-92), Yankees (1993-97) and Devil Rays (1998-99). He retired following the 1999 season with a .328 career batting average and 3,010 hits in 2,440 games. Boggs collected 578 doubles, 61 triples and 118 home runs while driving in 1,013 runs. He drew 1,412 career walks and finished with a career .415 on-base percentage.
On deck: After 159 games, the season comes down to three games against the Yankees, beginning with Friday's matchup between Boston lefty David Wells (14-7, 4.47 ERA) and New York right-hander Chien-Mien Wang (8-4, 4.02 ERA).
Mike Petraglia is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.