The 37-year-old Fletcher has played in 235 consecutive games entering Monday -- every game in his 15-year NFL career.
He hurt his left ankle against the Philadelphia Eagles on Nov. 18, but played on Thanksgiving against Dallas. Williams, already dealing with ankle and shoulder injuries, picked up a left thigh bruise against Dallas when kneed by a teammate.
Giants receiver Domenik Hixon is inactive for a second game in a row with an ankle injury. But safety Kenny Phillips (right knee), defensive end Jason Pierre-Paul (back) and offensive tackle David Diehl (shoulder) are active. Sean Locklear is expected to start for Diehl.