Roethlisberger left last Thursday's 14-3 win over Cleveland during the second quarter after turning the ankle while getting sacked. He returned to throw for 178 yards and a touchdown in the second half.
Neither Roethlisberger nor center Maurkice Pouncey, who is also dealing with a sprained left ankle, practiced on Monday. But that didn't stop Pouncey from declaring he expects to play, and expects Roethlisberger to do the same.
"I am fine. We`re both fine," Pouncey said after practice on Monday, according to the team's official site. "We'll be alright to go on Monday Night Football. We are both fine. We are going day-by-day and taking precautions. We will be fine."
Tomlin said Roethlisberger will have to practice at some point this week if he intends to play, adding he believes the extra day of rest will almost certainly benefit the quarterback.
Linebacker LaMarr Woodley (strained left hamstring) and defensive end Ziggy Hood (right hamstring) are both expected to play.
The Associated Press contributed to this report.