From Newark Star-Ledger:

The Giants returned to practice today in preparation for their playoff game on Jan. 11. While TE Kevin Boss (ankle/concussion), DT Barry Cofield (knee) and CB Aaron Ross (concussion) were back in action, seven players are not practicing (their recent injuries are listed, though these haven’t been confirmed as the actual reasons for their absence from practice):

RB Brandon Jacobs (knee)
DE Justin Tuck (knee)
RT Kareem McKenzie (back)
WR Domenik Hixon (foot/ankle)
S Michael Johnson (thigh)
TE Michael Matthews (ankle)
LB Zak DeOssie (unknown)