Speaking at the CC Sabathia and Friends charity softball game this week, Barber told reporters his records "don't have a chance" if Barkley stays healthy.
"He can be one of the greatest ever," Barber said, according to NJ.com. "Physically, he's a freak. I'll parallel him to Adrian Peterson. When I first met Adrian, I looked at his muscular and body structure and was just in awe ... When you pair that with a passion and desire to be great, you get an Adrian Peterson."
Barber ran for 10,449 yards in 10 years with the Giants. He was a second-round pick in 1997 and played his whole career in New York.
Barkley ran for 1,307 yards and 11 touchdowns last season. He was named Offensive Rookie of the Year.
Barkley also caught 91 passes for 721 yards and four touchdowns. The former Penn State standout was the No. 2 overall pick in the 2018 NFL Draft.