Changes? Hold Tight?

[phil]

I'm currently in first in a 10 team 5x5 roto mid-season league. I'm pretty satisfied with my team. I'm not necessarily looking to make any trades, but wanted some input on any areas of upgrade that anyone can see to secure my position in the league standings. My roster is as follows:

C: Lieberthal
1B: Nevin
2B: Soriano
3B: Blalock
SS: Furcal

OF: Berkman
Ordonez
Edmonds
B. Giles
T. Nixon

2B/SS: M. Giles
1B/3B: Konerko
Utility: K. Millar

SP: Schmidt
SP: Colon
SP: Webb
SP: Harden
SP: J. Williams
SP: Escobar
CL: Foulke
CL: Cordero
Rel: R. Soriano

I've tried to pick up another closer, but other teams either will not trade or are asking ridiculously high returns. I'm currently 5th in saves, with a 3 save lead over sixth. Any help will be appreciated. Specific suggestions of players to use in upgrades are encouraged.
Thanks.