Citing sources, KRIV-TV on Saturday reported Matsui had passed his physical, clearing the way for the free agent to sign a contract with the Astros. Matsui arrived in Houston on Friday night.
Astros general manager Ed Wade does not comment on negotiations.
Matsui, a 32-year-old switch-hitter, played for the National League champion Colorado Rockies this year and batted .288 with four home runs and a .342 on-base percentage. He will succeed the retired Craig Biggio as Houston's starting second baseman and likely bat second in the lineup behind center fielder Michael Bourn and in front of right fielder Hunter Pence, first baseman Lance Berkman and left fielder Carlos Lee.
Matsui was successful on 32 of 36 stolen base attempts during the 2007 season and his stolen base total was the ninth most in the NL. He also scored 84 runs.
Matsui played well in the postseason, batting .304 overall, including .417 with a grand slam and six RBIs against Philadelphia in the National League Division Series and .294 in the World Series against Boston.
Jim Molony is a writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.