Carragher was suspended from his television punditry role after being caught on camera spitting through the passenger window of a car following a verbal exchange with the driver, whose daughter was sitting beside him and was hit by the projectile.
Fellaini was described as "a menace in the worst possible sense" by Carragher in a newspaper column two years ago, prompting the Belgium international to describe the former England star as the "champion of blah-blah and the world champion of breaking legs".
But Fellaini has once again taken aim at the 40-year-old, making reference to his actions in the wake of United's 2-1 win over Liverpool in March.
"How can someone like Carragher lecture me?" Fellaini told Sport/Voetbal magazine.
"The guy who spat on a girl from his car after Manchester United-Liverpool.
"You know, the critics help you progress, you end up working more, you want to show them they are wrong."
Fellaini has been limited to 15 Premier League appearances for United this season because of injury, but scored his fourth goal in the competition when he netted the injury time winner against Arsenal on Sunday.