The team said Maualuga sprained his left ankle during practice last Thursday. He wasn't active for a 27-17 victory over the Indianapolis Colts on Sunday.
The Bengals are 4-2 heading into their bye this week, with their defense ranked among the NFL's best.
Maualuga declined to talk to reporters as he passed through the locker room Monday, supporting himself with two metal crutches. Coach Marvin Lewis hasn't given any indication how long Maualuga will be out.
The Bengals could have cornerback Adam "Pacman" Jones back after the bye. Jones said Monday that he has been cleared to return from offseason neck surgery.
Copyright 2011 by The Associated Press