"We haven't taken a physical," Mihara said. "After the physical, we will definitely do that, because it's our company's policy not to speak about the situation while it is not finalized."
Mihara said the company he was referring to is Athlete Dream Management Inc.
Astros GM Ed Wade does not comment on negotiations. Calls to Matsui's agent Arn Tellem were not returned. Sources told MLB.com Friday night that the two sides had reached verbal agreement on the key issues and that the deal with Matsui was "very close" but not finalized.
The Astros had made an offer to Matsui last week and Wade had previously confirmed the team was interested in the 32-year-old switch hitter, who played for the National League champion Colorado Rockies this year.
Matsui, who will succeed the retired Craig Biggio as Houston's starting second baseman, hit .288 with four home runs and a .342 on-base percentage.
Once Matsui signs on the dotted line, the Astros will have three players on the roster with Major League experience at second base including the recently signed Geoff Blum and Chris Burke, who entered the offseason as the heir apparent to Biggio.
Burke, 27, hit .229 in 111 games last year, but never really had a set position as the Astros used him in center field, second base and even shortstop on occasion. During 2006, in just 366 at-bats Burke hit .276 with nine homers, 40 RBIs and a .418 on-base percentage, a performance that seemed to stamp him as the club's second baseman of the future.
Matsui's signing, however, could make Burke the odd man out. The Astros have been seeking a closer since trading Brad Lidge and could use Burke in a trade package to address that vacancy.
A former first-round (10th overall) Draft choice in 2001, the University of Tennessee product has drawn interest in the past, most notably from the Chicago White Sox and Oakland A's. The Rockies are believed to be interested in Burke as a possible successor to Matsui.