HOUSTON -- Astros general manager Ed Wade doesn't like to wait around if he sees an opportunity he likes.

"I'm not one who tries to play two sides against each other trying to get a better deal, because too many times I've seen things fall apart," Wade said. "If there's something that makes sense for us now and in the long term, it's something we'll do sooner rather than later."

Whether signing free agents or pulling the trigger on trades, Wade hasn't wasted any time since taking over as Houston's GM.

Heading into next week's Winter Meetings in Nashville, Tenn., he has already made significant changes to the Houston roster:

• Wade acquired center fielder Michael Bourn, reliever Geoff Geary and third-base prospect Mike Costanzo from the Phillies for reliever Brad Lidge and infielder Eric Bruntlett. Bourn will be the starting center fielder and bat leadoff.

• The GM sent center field prospect Josh Anderson to Atlanta for right-hander Oscar Villarreal, giving the Astros another veteran right-hander for the bullpen.

• Free-agent infielder Geoff Blum was signed to take over Bruntlett's role as utility man/pinch-hitter/late-inning defensive replacement.

• Free-agent catcher Brad Ausmus was re-signed to a one-year deal. Ausmus also will help groom youngster J.R. Towles to take over everyday duties.

• Free-agent outfielder Yordany Ramirez was signed and added to the Major League roster. Ramirez is highly regarded by the Astros and figures significantly in their future plans.

Wade or one of his assistants has made contact with no fewer than a dozen free agents, and the club has an offer pending to at least one -- second baseman Kaz Matsui.

If Matsui decides to pursue other options -- and several other teams, including Houston's division rivals, the Chicago Cubs, are interested -- the Astros will continue to look for keystone help. Among players on the roster who have a shot to succeed the retired Craig Biggio at second base, Chris Burke is the leading candidate.

"We're always looking to improve wherever we can," Wade said. "That's not to say [Burke] won't be our starter. His situation hasn't changed -- he needs to continue to work hard and knock our socks off next spring."

Ideally, Houston's next second baseman also will be a prototypical No. 2 hitter with the ability to hit behind Bourn and in front of Hunter Pence, Lance Berkman and Carlos Lee. It is a crucial role, and why the Astros are scrutinizing every potential option.

The trade of Lidge left another crucial role open. Houston is without an experienced closer, although Chad Qualls had a brief stint at the job.

Winter Meetings

"We've got plenty of time to address that," Wade said. "There are a number of scenarios we're considering."

Wade won't get into specifics, but rest assured he will be a busy man in Nashville as the Astros try to find Lidge's successor. The club is looking for additional bullpen help besides a closer, and signed former Astros reliever Doug Brocail to a one-year deal on Tuesday.

After being outbid for free agents Francisco Cordero and Scott Linebrink, the Astros have been in touch with Paul Cohen, the agent for free-agent right-hander Troy Percival, and also have contacted the agents for Jeremy Affeldt (Michael Moye), and David Riske (Nez Belleo).

The Astros also would like to add at least one starting pitcher, and other free agents the team has contacted who are still available include second baseman Tadahito Iguchi and starting pitchers Randy Wolf and Jon Lieber.

The Astros enjoy some payroll flexibility despite having six players -- Burke, Qualls, right-handers Brandon Backe and Dave Borkowski and infielders Adam Everett and Ty Wigginton -- eligible for arbitration.

Of the club's free agents, Mike Lamb, Mark Loretta, Orlando Palmeiro, Brian Moehler and Jason Jennings, the Astros would like to have Lamb, Loretta and Palmeiro back but won't sign all three.

Those areas are, of course, secondary to the closer and second-base situations.

"We've still got a lot of work to do," Wade said.

The thin free-agent market and limited leeway on the trade front are impediments but not airtight barriers from further deals.

"Sometimes at the Winter Meetings things arise that you weren't expecting -- other teams that indicated they weren't interested in doing something [at the GM meetings] have changed their minds," Wade said. "Or other guys they were after have signed elsewhere, so they're focusing on other options. We'll see when we get to Nashville."