I've noted that those in our line-up that hurt our offense the most also happen to be our worst on defense this year. At least outside of Simmons struggles in the 8th spot while playing great defense at short. BJ Upton according to DRS is now a -9 in centerfield, that is already a lot worse than last year. BJ was actually fine in centerfield according to DRS last year. He also started well this year on defense, I remember him being at 4 or 5 DRS at one point. Which tells me he's been about -13 or 14 since his good start. CJ who also has a below .300 OBP and below .700 OPS has been our worst on defense. I noted his -10 DRS a week ago, make that a -12 DRS now for Chris Johnson. CJ has no range to speak of and is one of the worst third basemen I've seen at fielding bunts. He is just too slow to react and doesn't have the arm to make up for it. So for anyone asking if Peraza can play third. How about asking can he possibly do worse there than Chris Johnson? If so that would surely take some doing given Peraza's skill set.
To sum it up, I'd argue that we need to look to upgrade third and/or centerfield soon if we want to make the playoffs. I see our shot at the division and the playoffs probably going down the drain if neither happens (esp. considering the rate Fredi is costing us with his managing). The good news is that even if we only replace one of them we could both upgrade on defense and offense at those positions since they happen to be costing us the most runs with their bats and their gloves. Plus we'd be better off even if we replaced one of them with someone the same on one side that simply upgrades just the offense or the defense. A few more runs scored and a few more runs saved can be the difference in close games.
Lastly, I'd also argue that both Heyward and Simmons deserve a lot of credit for what they do to make up for most others on defense. We lost a ball game by a run recently that we rested Simmons and one of those runs scored on a failed DP Simmons often turns. Further, La Stella who isn't known for his defense has the second best DRS among our infielders. Not that -1 DRS is anything to write home about, but is sure blows away -12 DRS from CJ and what we saw from Uggla. While Heyward has led everyone in DRS this year. Heyward's amazing defense is even more important since both Upton's have cost us runs on defense. But Justin brings it with the bat unlike his brother BJ Upton.