He immediately jogged off the field and was evaluated for a concussion by trainers before being walked back to the locker room. He was later ruled out.
Kamara was hurt when he was swarmed for a 4-yard loss on a screen pass and absorbed a helmet-to-helmet hit on a tackle by Falcons linebacker Deion Jones.
He posted on Twitter early Friday morning that he didn't seem too worried about missing any additional time.
Right back at it next week. Hellyatalmboutt 🕺🏾⚜️
— Alvin Kamara (@A_kamara6) December 8, 2017
New Orleans also lost three starters on defense.
The 22-year-old Kamara has emerged as a front-runner for the NFL's Offensive Rookie of the Year award with 608 rushing yards, 639 receiving yards and 11 touchdowns. The third-round draft pick out of Tennessee ranked second in the NFL with 990 total yards from scrimmage from Weeks 6-14 -- behind only the Steelers' Le'Veon Bell.
Should Kamara be sidelined, veteran Saints running back Mark Ingram should play an even bigger role. Ingram has been equally effective as part of New Orleans' dynamic running back duo. He ranks third in the NFL with 882 scrimmage yards since Week 6. Ingram and Kamara are on pace to become the first duo to surpass 1,500 scrimmage yards in the same season.
Ingram started and took the first carry for the Saints despite being listed as questionable for Thursday's game with a toe injury.
Saints rookie defensive end Trey Hendrickson limped off the field and rode a cart back to the locker room after suffering an ankle injury when he planted his foot awkwardly. He did not return.