Toronto, Canada – Grant, 31, was placed on injured reserve because of an injury similar to the one that ended his season in 2008 after eight games.
Grant, a first-round pick of the Saints in 2002, anchored the left side of the line and started in all 16 regular season games. He had 53 tackles and 5-1/2 sacks.
The Saints finished the regular season top of the NFC South with a 13-3 record but enter the playoffs on a three-game losing skid.
The team said they had re-signed veteran defensive end Paul Spicer, who was released in pre-season.
(Writing by Frank Pingue, editing by Justin Palmer)