Roethlisberger practiced for the second straight day on Thursday, and Tomlin is very comfortable with him returning to action following a three-game absence.
Roethlisberger suffered rib and shoulder injuries in a Week 10 home win against Kansas City.
Byron Leftwich replaced Roethlisberger the following week and finished the club's home loss to Baltimore despite suffering a rib fracture.
Veteran signal-caller Charlie Batch took over the reins in a Nov. 25 loss at Cleveland, then directed a fourth-quarter comeback this past Sunday at Baltimore.