Straight from Eddy Wade's mouth:

At this point, we’re prepared to commit to Tommy Manzella playing shortstop.

The possibility remains that Tejada could return as a third baseman.

Tommy Manzella grades anywhere from good to very good at shortstop. AstroAndy did a fine comparison between Manzella and former Astro Adam Everett a few months ago. Replacing this kind of defense with Manzella's defensive abilities at short would definitely be a boon. 

As far as being able to retain Miguel Tejada as a third baseman, I don't know if that would be in the cards. His Bill James projection for 2010 is actually better in terms of runs created per game as compared to 2009. The million dollar-plus question will be if that production is worth spending X amount of dollars more on the veteran Tejada vs. some sort of platoon with Blum/Kepp/C. Johnson.

With Lance Berkman, Geoff Blum, Kaz Matsui and Jeff Keppinger already assured of spots on the club in 2010, Ed Wade will have decisions to make on which other infielders to bring in. It seems as if Tommy Manzella will play shorstop, as a trade or free agent signing isn't likely. While Chris Johnson has shown promise, don't look past Jeff Keppinger as a good option to be a starter on this team. He's not going to get David Wright AB's, but he is right at the peak of his career and is looked at as being a solid contributor in 2010. A fairly cheap contract makes him nearly as attractive as Johnson for the cost conscious Astros.

Bottom line, this was the first real indication of what changes we can expect in our 2010 Astros. For those who missed having a superb defensive shortstop, your wish looks like it may be coming true. Tommy Manzella will need time to adjust to major league hitting, but he has shown the ability to approach Everett's level offensively. That may not wow you, but remember that the cost is right with Manzella. Get used to hearing that sort of rationalization from the Astros camp. Keep in mind as well that Gio Mier is drawing rave reviews as the best defensive shortstop from the 2009 draft and his bat has been better than advertised so far as a professional. View Manzella however you want- a defensive savant, a stopgap, Adam Everett, 2.0. He makes the league minimum, and when your team is dominated by three player's salaries, those are the sort of trade offs a team must make.

As for Miguel Tejada, it doesn't appear that he will be back as an Astro, despite the door being left open for his return. He turned in a nice offensive season and as stated earlier is supposed to be even better in 2010. It's probable that another club gives him a shot at third, and does so with a contract whose value is close to eight figures per season. The Astros have three serviceable to slightly above serviceable options at third base, which leaves Tejada as the odd man out in my mind.