Blow up the team. That's what I'd do.
Ok, not really, but the Astros do need more production out of LF and DH. There isn't much left in the free agent bag. The free agent who I would have seriously considered -- Melky Cabrera -- actually just got signed by the Indians (and for a fairly insignificant amount). Matt Holliday is still available. Minor league deal? Anyone?
If we assume that Tucker isn't coming up yet, we are talking about the same AAA guys who've been up and down -- Davis, Kemp, Reed. Davis and Kemp are having great seasons so far in AAA. The only new name to throw out is Drew Ferguson who has been raking (even though his batting average is now down to only .362).