Backup offensive lineman Adam Koets will start in O' Hara's place.
O'Hara, 33, injured the foot during the Giants 41-35 victory over Dallas on Oct. 25 and has been wearing a protective boot on his right foot. O'Hara did not practice at all during the week, but he was seen working out Friday afternoon.
Head coach Tom Coughlin had said at the beginning of the week he was told it was a "mild" injury before later saying the team would evaluate it day by day. O'Hara could be out one more week with the sprain.
This is the fourth game that O'Hara will miss this season. He was inactive for three straight games, starting with the contest against Tennessee on Sept. 26, with an injured left ankle and left Achilles. That injury is not related to his current ailment. O'Hara returned to the starting line up Oct .17 against Detroit and has started the past two games.
The Giants have also ruled out fullback Madison Hedgecock (hamstring) and Tackle Will Beatty (foot) for Sunday's game. Kick/punt returner Darius Reynaud is questionable after pulling his right hamstring during practice Friday.
Matt Ehalt is a regular contributor to ESPNNewYork.com.