Houston traded him to Oakland in February 2013 as part of a five-player deal that brought Chris Carter to the Astros.
''To be honest, I was a little disappointed,'' Lowrie said Friday. ''I liked the idea of being a part of an organization that was building something, pretty much from the ground up. And that's not to say my experience in Oakland wasn't great - we made the playoffs both years I was there, won the division the first year. ... That was good for me, but I'm happy to be back.''
Given the chance to pick a team as a free agent, Lowrie agreed in December to a $23 million, three-year deal with the Astros.
He returns as a proven 31-year-old shortstop.
''He's entering the stage of his career where presence matters, where his steadiness matters,'' manager A.J. Hinch said. ''He and I are very aligned on the preparation component of the game, and having him be familiar with (Jose) Altuve in the middle of the infield is fantastic for me.''
Lowrie and Altuve formed Houston's double-play combination in 2012, Lowrie's only season with the Astros and the first full season in the majors for Altuve, now a two-time All-Star and the reigning AL batting champion.
Lowrie hit .290 with 15 homers and 75 RBIs two years ago as Oakland won the AL West. A broken index finger cut into Lowrie's production last season, when he batted .249 with six homers and 50 RBIs.
''We have guys who have come in from other organizations that have had some success, and so that raises the expectations across the board,'' Astros general manager Jeff Luhnow said. ''Our fans expect more this year, and rightly so.''
After Houston's third full-squad workout of spring training, Lowrie said he saw ''a lot of familiar faces, and a lot of veterans that I've played against for a long time.'' That is part of the reason he is here.
''I think the best combination you can have is young talent mixed with a good group of veteran guys,'' he said. ''I got a chance to sit down with A.J. and see where he saw the team going, how he planned on running the team. That made a big difference in my decision.''
Lowrie plays the position the Astros hope to fill eventually with Carlos Correa, the No. 1 overall pick of the 2012 amateur draft. The 20-year-old Correa, who was set back last year by a broken right ankle and broken right leg, has yet to play above Class A.
NOTES: RHP Roberto Hernandez is working out his visa issue in the Dominican Republic. Hinch said it will not be a problem until the exhibition games begin on March 5. ... The Astros have been concentrating on ''individualized defense'' and baserunning under coach Gary Pettis. ''We're going to be talked about because of power, but we're going to be a good baserunning team,'' Hinch said. ... The Astros have three off-days on their March schedule, but Hinch said two are likely to be filled with either a ''B'' game or intrasquad game. ... Collin McHugh is tentatively scheduled to pitch Houston's spring training opener Thursday against the Phillies.