keepers for fantasy baseball?

I know this is quite early but I would like to know who I should consider keeping for fantasy baseball next year. My team has won the championship the last two years and would like to have a three-peat. The league I play in goes head-to-head and runs 6x6 stats (standard 5x5 with OPS and QS added). There are clearly some pick-ups that were made in the last match-up to win the title. Here is my roster:

C Buster Posey, SF C, 1B

1B Paul Goldschmidt, Ari 1B

2B Daniel Murphy, NYM 2B

2B Brandon Phillips, Cin 2B

3B Ryan Zimmerman, Wsh 3B

3B Adrian Beltre, Tex 3B, DH

SS Elvis Andrus, Tex SS, DH

SS Jean Segura, Mil SS

OF Justin Upton, Atl OF

OF Alex Rios, Tex OF

OF Nick Swisher, Cle OF, 1B, DH

OF Michael Cuddyer, Col OF, 1B

P Yu Darvish, Tex SP

P Casey Janssen, Tor RP

P Glen Perkins, Min RP

P Hyun-Jin Ryu, LAD SP

P Bruce Chen, FA SP, RP

P Tanner Roark, Wsh SP, RP

P Hiroki Kuroda, FA SP

P Anibal Sanchez, Det SP

P Hisashi Iwakuma, Sea SP, RP

P Travis Wood, ChC SP

P A.J. Griffin, Oak SP

P John Lackey, Bos SP

P Dillon Gee, NYM SP

Which two would you keep?