I think there is no everyday lineup with Lee out. So all I have is individual pieces. Tejada is not a great defender any longer.
Did not claim he was a 'great' defender, just that he was a 'plus' defender (and although he's no Adam Everett at SS, his play has been excellent). And for those reliant on such things, I'll throw in some stats for good measure... Of qualifying SS (19) this year (2 games played at the position per 3 team games) Tejada is #2 in zone rating (The percentage of balls fielded by a player in his typical defensive "zone," as measured by STATS, Inc.), #3 in assists and #6 in fielding percentage. Would seem to fit the 'plus' defender category to me (even considering his #12 in ZR).
Matsui has what looks to be a chronic back problem. Bourn plays every 3 or 4 days at this point, and I hate Quintero's receiving skills. He's better than he has been behind the plate, but he's still not any thing close to a plus defender.
Matsui should still end up averaging 4 of 5 games through the rest of the year. Admittedly it was a stretch to call him a 'plus' defender, but he is definitely league average. Either way, is not a 'problem.' Center field is still a plus defense position for the Astros as well. As for Q, I'll let others more knowledgeable than myself opine as to his defensive skills.
Corner defense is mostly bullshit, but since you brought it up...I disagree that Pence is a good fielder. I think his speed bails him out. Whoever is in left is poor (unless you're talking about Erstad). Erstad is the defacto starter in Center. Wigginton and Blum at third are capable, but hardly what anyone would consider more than average defenders.
Although Pence looks like a Spaz in right, his speed does bail him out. The numbers (ZR, RF and FPCT) show him as a 'plus' defender. I added the 'average' to it because he simply does not look like a 'plus' defender. As for Wigginton/Blum, I believe I referred to them both as 'league average.' Again, none of which I would define as a 'problem'.
And good for Lance Berkman. He plays stellar defense at 1st...the least important defensive position on the field.
You said the defense was a 'problem.' I went position-by-position with my arguments as to why I thought you were full of crap. Given first base makes up part of the Astros defense, thought it relevant to note. Seems you disagree.