Pitchers Doug Brocail and infielder Aaron Boone can also file for free agency, but neither is likely to return to the Astros. Houston has already turned down Brocail's option for 2010, Hampton will miss all of next season with an injury and Boone may retire.
Astros assistant general manager David Gottfried has had several conversations recently with Larry Reynolds, the agent for Hawkins, and he touched base with the agent for Michaels on Wednesday. Wade spoke with Diego Bentz, Tejada's agent, last week.
"We know Hawk likes our situation and we feel he did a tremendous job for us ever since he joined the club, and we'd like to be able to retain him," Wade said. "I wouldn't view anything as close at this point. When you get to this stage of the offseason, it behooves the players to file and see what the market presents to them. Our hope is that we're able to get a number of guys back, including Hawk."
Valverde led the league in saves in 2007 (for Arizona) and 2008 (for the Astros) and went 4-3 with a 2.33 ERA and 25 saves last season for Houston despite missing significant time with a calf injury. He made $8 million last season and is likely to command a raise in the open market, which could price him out of the Astros' range.
Tejada made around $15 million last season, but would need to take a significant pay cut to return to Houston despite leading the team in hits (199) and RBIs (86). Tejada's future could be at third base, but the Astros likely wouldn't want to sign him to a long-term deal.
Hawkins has posted a 1.71 ERA in 89 games in 1 1/2 years with the Astros and could be an option at closer if Valverde departs. Michaels hit .237 with four homers and 16 RBIs, but batted .311 in the second half, and Erstad hit .194 in 150 at-bats.
"I would definitely like to return," Michaels said. "I really like playing there and I like the direction and what has happened this offseason. It's a great place to play and my wife felt comfortable there."
But before the Astros can become aggressive in signing their free agents, Wade said he needs to get a better idea of the club's overall payroll picture.
The Astros had a record $107 million payroll in 2009, but that is likely to be reduced. Four players -- first baseman Lance Berkman, left fielder Carlos Lee, pitcher Roy Oswalt and second baseman Kaz Matsui -- will make a combined $54.5 million next year.
What's more, All-Star right fielder Hunter Pence, team Most Valuable Player Michael Bourn and team Pitcher of the Year Wandy Rodriguez are all arbitration-eligible for the first time and will command large raises.
"We're of the mind that all of the guys that are eligible are a good fit for us, and we'll sort through that at the proper pace," Wade said. "We're in the stage of the doing workups to determine values."
With his entire coaching staff, including manager Brad Mills, finally in place, Wade will return from Arizona on Friday before leaving Sunday for the three-day general managers' meetings in Chicago.
"The filing period starts [Monday] and with the general managers' meetings beginning next Monday night, I think it's going to be quiet until you get the full filing period complete and know exactly who's on the market," Wade said. "That will give every ballclub a better idea what potentially might be done from a free agent standpoint, and once the club has a chance to wrap its arms around what the market is going to be like then it will create a clearer picture of what you may do from a trade standpoint."