Slumping Players...Time to make some changes????

[Matthew3046]

12 team roto not keeper using R HR RBI SB AVG W SV K ERA WHIP
C I. Rodríguez
1B T. Hafner
2B J. Reyes (NYM - 2B,SS)
3B A. Ramírez (ChC - 3B)
SS K. Matsui (NYM - 2B,SS)
CI E. Chávez (Oak - 3B)
MI C. Barmes (Col - 2B,SS)
OF A. Jones (Atl - OF)
OF Lu. González (Ari - OF)
OF R. Hidalgo (Tex - OF)
OF J. Dye (CWS - OF)
OF M. Alou (SF - OF)
Util J. Posada (NYY - C)
DL L. BerkmanDL (Hou - OF)
P R. Johnson (NYY - P)
P M. Rivera (NYY - P)
P D. Graves (Cin - P)
P R. López (Bal - P)
P D. Willis (Fla - P)
P J. Marquis (StL - P)
P J. Moyer (Sea - P)
P B. Penny (LAD - P)
P J. Tavárez (StL - P)

I obviously need some speed and I'm short a closer. What has me stumped though is lack of production from my big name guys has got me waivering in HR and average. What do you guys think...any suggestions???? Is it time for an overhaul???