The other day, I was prompted with a question: given cost/fit, who do I think would be the Giants' best trade acquisition. Carlos Beltran obviously came to mind, as he's a guy that would undoubtedly bolster the lineup. He's hitting .285/.377/.503 on the season, and given the fact that he's a rental on a rather lucrative contract, the cost to acquire him probably wouldn't -- or rather, shouldn't -- be too high. The estimated gain from Beltran over Cody Ross or Pat Burrell would be roughly one win, perhaps more (if he continued to hit this well).
The offense certainly stands to benefit from an upgrade like Carlos Beltran, but the outfield is not the source of the Giants' offensive struggles. Their outfield offense (especially when platooned correctly), is anywhere from average to above average. The Giants have a couple positional weaknesses (catcher, middle infield) that need to be addressed.
Giants catchers have been pretty decent over the last 30 days, and that (even though it's unsustainable), paired with the fact that they're familiar with the pitching staff, has convinced me the Giants won't make a move for a catcher. And there really aren't many options out there anyway. They didn't seem too interested in Ivan Rodriguez; Geovanny Soto and Ramon Hernandez are not actually going to be traded; at this point in the season, I just don't see the Giants giving up something in order to turn Chris Stewart into Rod Barajas or Ronny Paulino.
A realistic target -- a low-cost option that would improve the Giants' middle infield rather significantly -- is Jamey Carroll. Carroll, age 37, isn't a spectacularly attractive option, but he's definitely a huge step up from Emmanuel Burriss/Bill Hall. While he's no defensive whiz, he's playable -- perhaps even average -- at third base, second, and shortstop. He's having himself a fine season, too, hitting .297/.368/.366. He has little power (just 12 career home runs in 3240 plate appearances), but makes up for it with good on-base skills -- over 2009-2011, he's posted respective OBPs of .355, .379, and .368, and he has a career on-base percentage of .357...Carroll would solidify the Giants' middle infield with a right-handed bat, and unlike Bill Hall (.211/.261/.314 along with sub-par defense in 2011), is not terrible at baseball.
Carroll's contract is up after this year, meaning he's a rental. Per Baseball-Reference, Carroll is owed just $1.8MM in 2011 (some of which has obviously been covered by the Dodgers so far this season). I have to think he's worth four or five million in surplus value over the rest of the season, meaning he's worth a grade B hitting prospect in a trade; I bet the Giants could acquire him at a lower price, though. Tossing out a few names here, but I wonder if Tommy Joseph (19-year-old catching prospect at San Jose, with good pop, rated a C+ prospect at the beginning of the year) or maybe Roger Kieschnick would be enough to pull off a trade for Carroll. That'd certainly be worth it.