The signing of Michaels, who will likely be a backup outfielder, puts the Astros' 40-man roster at its max, meaning the club will be limited to signing players to non-roster Minor League deals the rest of the offseason. Houston did just that Monday, inking left-hander Gustavo Chacin and inviting him to Spring Training.
"It's nice to return to a place you are familiar," Michaels said. "Not just with the guys on the team, but with the surroundings and stuff like that. I'm glad it was able to be worked out."
Michaels, 33, hit .237 with four home runs and 16 RBIs in 102 games with the Astros last season. All four homers and all but five of his RBIs came after July 5. He started at all three outfield positions, including four in left, 12 in center and two in right, and hit .274 as a starter.
"Early in the season, he didn't get a lot of playing time other than pinch-hitting, and he struggled," Astros general manager Ed Wade said. "He got more playing time in the second half and responded in a way we thought he was capable of responding. I expect we'll see more of that second half player as we move forward.
"He's versatile, can play all three outfield positions and he's a good pinch-hitter and a guy you can run out there [to start] three or four days in a row and know he'll do a good job. The veteran presence doesn't hurt, either."
Michaels, whose wife gave birth to the couple's first child -- a daughter -- two weeks ago, is eager to play for new manager Brad Mills, who was on the coaching staff in Philadelphia when Michaels was coming up with the Phillies.
"He's a great leader," Michaels said. "I think he's going to be tremendous for our team, and a lot of the guys have said good things about him. I look forward to the upcoming season."
Chacin, 29, spent last season in the Phillies organization, splitting time between Triple-A Lehigh Valley (18 starts) and Double-A Reading (two starts). In his 20 starts combined, Chacin was 9-4 with a 3.20 ERA. He is currently pitching for Caracas in the Venezuelan Winter League and owns a 2-3 record and a 4.50 ERA in seven starts.
Chacin, who won 13 games in 34 starts for Toronto in 2005 while working with new Astros pitching coach Brad Arnsberg, will be thrown into the mix at Spring Training to win a spot in the starting rotation.
"He's got some pretty good experience and we're trying to add depth and competition and at the very least have the ability to reach down to Round Rock if we have to come up with replacements when we need them," Wade said. "He's coming to big league camp to put his best foot forward, and you never know what's going to happen."
By trading for reliever Matt Lindstrom and signing free-agent pitcher Brandon Lyon and third baseman Pedro Feliz, the Astros appear to be done with major additions after the re-signing of Michaels. But Wade expects a lot players will be coming to Spring Training camp with the Astros and other teams trying to win jobs.
"Those players will sign, and at the end of Spring Training you're going to have another group of free agents out there and when teams take their 40-man roster down to 25 for Opening Day," Wade said. "We're going to be the land of opportunity."
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.