The sources said it is expected to be "a true game-day decision."
Kickoff on Sunday is at 1 p.m. ET in Baltimore.
Roethlisberger, who is officially listed as questionable, underwent surgery Oct. 17 to repair a torn left meniscus. He has been limited in every practice this week, though teammates have said Roethlisberger has gotten first-team reps.
Coach Mike Tomlin told ESPN and WDVE 102.5 after practice Friday that Roethlisberger "had a good day today" but said the team had not yet made a determination on his availability.
"We'll see how his body responds to the work," Tomlin said Friday. "We don't have to make the decision today, so we won't. We'll continue to push forward toward game day."
Backup quarterback Landry Jones started in place of Roethlisberger in the Steelers' loss to the Patriots in Week 7 before their bye week.
Roethlisberger, 34, was originally given a four- to six-week timetable to return after suffering the injury in a loss to the Miami Dolphins on Oct. 16.
The Steelers lead the AFC North with a 4-3 record.