Cook was injured during his second TD catch -- a terrific 26-yard grab, which he held on to despite being hit in the head by 49ers cornerback Ahkello Witherspoon and drawing an unnecessary roughness penalty.
Cook, who signed with the Saints in free agency this offseason, has really started to come on during the second half of the season, with four TD catches over the past four games. He has six touchdowns on the season.
Sunday's game between the Saints (10-2) and 49ers (10-2) has been a stunning track meet so far. San Francisco took a 28-27 lead at halftime in a game that was expected to be more of a defensive slugfest.