Drop Bartlett and Sanchez, pick up Edwin Jackson and Romero. Put Romero on the DL, and pick up another SP, maybe Carmona. You will increase your K's just by having more starters go out there for you. Other than that, try packaging 2 of your SPs for an elite SP, although that might be tough.
Bartlett is too good a player to just drop.
Especially since he is likely to get moved up in the order soon...remember he is currently hitting 8th. Thats not going to last with him hitting .350, 18 runs, 4 hrs, 13 rbis, and 7 steals. I would definitely just leave him Util and forget about him. However, he could definitely be packed with another player for a big trade.