The decision to send Pierce to the IR comes less than two weeks after he was originally diagnosed and ruled out "indefinitely."
Pierce, a nine-year veteran of the NFL and a former Pro Bowler, has led the Giants in tackling in each of the least three seasons and has been widely considered the team's vocal leader on defense since coming over from Washington in 2005.
The center of the Dallas Cowboys universe.
The Dallas Cowboys, New York's opponent on Sunday, can attest to that. Pierce was involved heavily, along with (surprise, surprise) Brandon Jacobs in the war of words between the teams--which began in the regular season and carried through to New York's playoff win over Dallas--in 2007.
This bitter exchange of verbal jabs has played no small part in the development of the rivalry, which now stands as (very) arguably the best, most provocative, of any in the NFC East and possibly the conference as a whole.
More recently, he gained notoriety for his involvement in the Plaxico Burress shooting incident, which consisted of driving the receiver to the hospital and taking the gun involved to his house; after questioning, the court opted against pursuing criminal charges against him.
Pierce, 31, will be replaced for the rest of the season by Chase Blackburn.