Myers spoke exclusively to MLB.com on Saturday about the trade, saying he was excited to be going to a White Sox team that's in first place in the American League Central.
"They're in first place," he said. "I'm pumped about that and to play for a team that's fighting for a championship. That's why I play the game, to win championships."
Myers, who closed for the Phillies in 2007, has saved 19 of 21 games this year for the Astros. He has a $10 million option for 2013 that vests if he finishes 45 games this year. He has finished 29 games so far. There's a $3 million buyout if the option doesn't vest.
The Astros are expected to pick up most of the remainder of Myers' $11 million contract for this year.
"I was happy they gave me an opportunity to re-establish myself as a starter, and this year they needed a closer," Myers said. "They had a couple of guys to pick from and they asked me to do it and I was happy to do it. I had a good time there. It was good for my family and everything and it was a good place to play. I guess it just didn't work out in the end for us."
The Astros also announced Saturday they have claimed 25-year-old right-hander Mark Hamburger off waivers from the Padres. Hamburger, who will be assigned to Triple-A Oklahoma City, has some Major League experience, appearing in five games in relief for the Rangers in 2011, posting a 1-0 mark with a 4.50 ERA. He has seen duty as a closer throughout his Minor League career and tallied a career-best 21 saves.
Myers, 31, signed a one-year deal with the Astros prior to the 2010 season and went 14-8 with a 3.14 ERA in 33 starts, earning him a two-year contract extension from former general manager Ed Wade. Myers went 7-14 with a 4.46 ERA in 2011 before being moved to closer prior to this year.
"Brett showed that he was a real team player by going to the bullpen for us and was very successful as our closer," Astros general manager Jeff Luhnow said. "We appreciate everything he has done for us."
Prospects acquired by Astros
- Blair Walters, LHP: The 2011 11th-rounder out of the University of Hawaii began the year in the South Atlantic League but earned a promotion up to the Class A Advanced Carolina League after 13 starts. He has a good sinking fastball and breaking ball. His changeup isn't as good, but he mixes pitches well and throws strikes. He doesn't have a huge ceiling but could pitch at the back end of a rotation.
- Matthew Heidenreich, RHP: A 2009 fourth-rounder, Heidenreich earned a promotion from the Carolina League to the Double-A Southern League this season. Still young, with a projectable frame, he throws a hard sinker that generates a ton of groundballs. His changeup is his next best pitch, and he also throws a slider. He's a strike-thrower who pitches to contact more than he misses bats.
- Top 20 Prospects: Astros
- -- Jonathan Mayo
Walters, 22, was 4-6 with a 3.96 ERA in 18 combined starts with Class A Kannapolis and Class A Winston-Salem this season while tallying 93 strikeouts in 97 2/3 innings with 22 walks. Walters, who was taken in the 11th round of the 2011 Draft by the White Sox, has a 13-6 record in his two Minor League seasons with a 3.99 ERA in 32 appearances (31 starts) with 165 strikeouts in 171 1/3 innings of work. He will be assigned to Class A Lancaster.
"The pitchers we are receiving are talented young prospects with big-league upside," Luhnow said. "They have had success in their young careers and we're excited to add them to the mix."
On Friday, The Astros shipped veteran starting pitcher J.A. Happ, veteran reliever Brandon Lyon and Minor League reliever David Carpenter to Toronto in exchange for seven players -- reliever Francisco Cordero, outfielder Ben Francisco, four Minor League prospects and a player to be named later.
It's the third major trade Luhnow has pulled off this month, having sent Carlos Lee to the Marlins on July 4 in exchange for two prospects. Earlier this year, he shipped veteran catcher Humberto Quintero and outfielder Jason Bourgeois to Kansas City for two Minor Leaguers.