Lucas Duda - Duda has started every game since the Beltran trade, so it looks like the Mets are going to try and live with his atrocious defense in the outfield for the time being. I can't believe they wouldn't be better off swapping him with Danny Murphy, but the what the heck, it's better for Duda's fantasy value. Duda has immense power potential, as evidenced by the 31 doubles and 27 homers that he's hit in the last two-thirds of a season at AAA. He's also managed to maintain over a .300 AVG down there, and he's still just 25. The defense is actually going to be key for him. I'd be surprised if he didn't hit enough to keep a lineup spot, but he may be relegated to 1B in the end, where the bar for adequacy is obviously higher. The Beltran deal gives Duda the opportunity he needs, and I think it makes him a clear pickup in most formats, but his long-term value will be tied as much to his positional eligibility than anything.
Paul Goldschmidt - The Brandon Allen deal has seemingly opened the way for Paul Goldschmidt to be the everyday 1B. Goldschmidt is 23 and sports a career minor league line of 317/406/620. He has little speed (despite his middling SB totals in the minors), but he can definitely hit. K totals will be an issue, but he's clearly worth owning in most formats right now and has tremendous power upside.
Jimmy Paredes - Paredes comes to Houston to start at 3B for a team that really is starting to resemble a AAA squad. That's not to say that Paredes has no positive qualities, because he has shown some ability across the board...at least if you don't count plate discipline. Paredes is just 22, so some growing pains are to be expected, but at the very least he should provide some speed, and he has enough power and AVG potential to be intriguing in NL-only formats already, and deep keeper leagues certainly.
Neil Walker - Despite a little bit less in the power department, there's been a lot to like about Walker's 2011 thus far, especially after a 7-game stretch that has seen him post six multi-hit games. An increased walk rate, more speed, and better defense don't give you an awful lot more fantasy value, but they help illustrate how Walker has become an integral part of an improving Pirate team. A bit less luck on balls in play this year has kept his AVG a bit lower than in 2010, but he's actually hit more line drives this season than last, and at age 25 I'd expect the power numbers to return to at least last year's levels in the near future. Walker remains a very solid option at 2B.
Zack Greinke - Greinke tossed his fifth straight quality start last night, picking up a huge win against the 2nd place Cardinals. Greinke has obviously been a victim of bad luck for most of this year, so perhaps this is turning around a bit. I could go through a handful of stats to prove this, or I could mention that Greinke's ERA of 4.41 pales in comparison to his FIP ERA of 3.01, and his xFIP ERA (fielding independent ERA normalizing HR/FB) of 2.22 borders on the ridiculous through this many IP. I have every confidence that Greinke will be very solid down the stretch and beyond.