The Los Angeles Dodgers have seen the Rockies and Giants getting bigger in their rearview mirror, so they added some power to try to pull away.
"I think it's made us stronger," Dodgers manager Joe Torre said after a 5-3 loss to the Diamondbacks. "We have a threat off the bench now, and in Garland we certainly have someone who knows how to pitch."
For players to be eligible for the postseason with a new team, transactions had to be completed before midnight ET on Monday.
Thome is batting .252 with 23 homers and 74 RBIs in his fourth season in Chicago. The five-time All-Star is 12th on the all-time home run list with 564.
ESPN The Magazine's Buster Olney reported earlier on Monday that the White Sox had sent a memo to teams around the league saying veteran players were available for trade. Thome, Jermaine Dye and Scott Linebrink were said to be on that list.
It's not immediately clear what role Thome will fill for the Dodgers. He has been exclusively a designated hitter the past two seasons and hasn't played first base -- the position he played earlier in his career -- since appearing in one game there in 2007. He hasn't played first base full time since 2004.
"I'm not saying you won't see Jimmy at first, but I want to talk to him," Torre said.
James Loney is the Dodgers' regular first baseman, but he has only nine homers.
Dodgers general manager Ned Colletti envisions Thome playing a role similar to the one Matt Stairs filled for the World Series champion Phillies last year -- he hit a key home run against the Dodgers in the National League Championship Series.
"We're not bringing him over here to play first base," Colletti said. "We're bringing him here to come off the bench and be a great influence in the clubhouse. He's one of the true great guys in the game.
"In fact, the night before the deadline he called me. ... He just said: 'I just want to be honest with you. I'd love to come. I want to help you guys any way I can. But playing first base is not something I'm going to be able to do -- maybe in an emergency situation, perhaps.'"
The Dodgers, who entered Monday's games 12th in the NL with 114 homers, reunite Thome with Manny Ramirez. The power hitters with a combined 1,106 homers were teammates on the Cleveland Indians in the 1990s and went to the '97 World Series together.
Garland is 8-11 this season with a 4.29 ERA in his first season with Arizona. He pitched in Los Angeles last season, going 14-8 with a 4.90 ERA for the Angels. He won 18 games in consecutive seasons for the White Sox in 2005 and 2006.
After Monday's game, Garland made what he called a "definitely weird" walk from the visitors' clubhouse to the Dodgers' room. He was scheduled to pitch the series finale against the Dodgers on Thursday.
"It's definitely a team I've always wanted to pitch for," said Garland, who was born in the northern suburb of Valencia and went to high school in nearby Granada Hills. "This is where the dream started for me."
Torre also said that Garland could start Thursday, against his old team, the D-backs, and that he will get the ball every fifth day.
The Dodgers will receive Thome and cash for minor league infielder Justin Fuller. The Dodgers said that Garland was acquired for a player to be named later.
Thome is owed $2,415,301 from his $13 million salary, and is eligible to become a free agent after the World Series.
Garland is due $1,161,202 from his $6.25 million salary. His contract includes a $10 million mutual option. He gets a $2.5 million buyout if the team declines and $1 million if he declines. Because he was traded, the Dodgers cannot offer him salary arbitration if he is a Type A free agent.
Thome goes from a third-place team trailing Detroit and Minnesota in the American League Central Division to the first-place Dodgers, who came into Monday night leading the NL West by six games.
Garland gave up five hits and a walk over seven sharp innings in a 9-0 victory over the Houston Astros on Saturday.
"He's somebody we had interest in this past winter and who we've watched for a while and have seen in our division. He's pitched in the postseason, he's been on a team that's won the World Series," Colletti said. "When you get to the month of August and you start looking for additional help and can add a veteran starter who can give you innings and is a winning-type player, you go for it."
In a separate move on Monday, the busy White Sox dealt pitcher Jose Contreras to the Rockies. The right-hander led the AL in losses with 13, against only five wins, and had a 5.42 ERA.
The Rockies get Contreras and cash for Triple-A right-hander Brandon Hynick. Hynick is 10-9 with a 3.83 ERA and two complete games in 26 starts this season with Triple-A Colorado Springs.
Information from The Associated Press was used in this report.