The Rangers made the announcement Tuesday after Lundqvist had an exam and met with specialists.
Lundqvist was injured Jan. 31 when he was struck by a shot by Carolina's Brad Malone. He finished the game and played two nights later. Further tests revealed the severity of the injury.
Lundqvist has been working out on the ice, but facing only low shots. The Rangers' career wins and shutouts leader was 16-4 with a 1.82 goals against average and one shutout in 20 games before the injury. Overall this season, he is 25-11-3 with a 2.25 goals against average and five shutouts.
New York has thrived behind backup Cam Talbot, going 15-2-3.