Astros general manager Ed Wade wouldn't comment on Myers, but sources told MLB.com the two sides had reached a one-year deal for $5 million with an option for 2011.
The Astros were believed to have been done making major acquisitions following the Winter Meetings after trimming payroll to nearly $95 million from last year's club-record $107 million, but the club will stretch it with the signing of Myers.
Myers, 29, started three Opening Days for the Phils and recorded the final out in the 2007 regular season, which helped Philadelphia clinch its first National League East championship since 1993. He also helped Philly win the '08 World Series.
Myers' injured right hip which he suffered in May required surgery in late June. The righty rejoined the team in September as a relief pitcher, but strained his right latissimus dorsi muscle and missed more time.
The addition of Myers is a boost to the Astros' rotation, which currently consists of Roy Oswalt, Wandy Rodriguez, Bud Norris, Felipe Paulino and Brian Moehler. Myers likely leaves Norris, Paulino and Moehler competing for two spots heading into Spring Training.
As general manager of the Phillies, Wade drafted Myers in the first round of the 1999 First-Year Player Draft. Myers went 14-9 as a starter in his first full season in the Majors in 2003 and went 11-11 in '04. He blossomed in '05, winning 13 games with a career-best 3.72 ERA. In '06, he led Philadelphia in wins, ERA, starts, innings pitched, strikeouts and winning percentage and signed a three-year, $25.75 million contract extension prior to the '07 season.
Myers was moved to the bullpen late in the 2006 season and eventually became the closer, saving 21 games. He went 5-5 with a 2.87 ERA in 48 relief appearances. He returned to the rotation in '08 after the Phillies acquired Brad Lidge and was Philadelphia's Opening Day starter that season, going 10-13 with a 4.55 ERA.
The biggest moves Houston has made this winter have been mostly to bolster its bullpen. It traded for Florida reliever Matt Lindstrom and signed Brandon Lyon to a three-year, $15-million deal at the Winter Meetings. It later added third baseman Pedro Feliz from Philadelphia on a one-year deal.