On Thursday, Andrew Gribble of the Browns' official website reported Griffin would start for Cleveland on Sunday.
The Browns promoted Griffin to the 53 man roster and waived Matt McCants on Friday, per Nate Ulrich of the Akron Beacon Journal.
Griffin began the season as the Browns' starting quarterback, going 12-of-26 with 190 yards and one interception in a 29-10 loss to the Philadelphia Eagles.
During the fourth quarter of that defeat, Griffin suffered a fractured left shoulder when he collided with Eagles cornerback Jalen Mills while trying to run out of bounds.
The Browns placed Griffin on injured reserve the following day, keeping him out of action for at least eight weeks. At the time, ESPN's Adam Schefter reported the expectation was the 2012 NFL Offensive Rookie of the Year would miss at least 10-12 weeks and possibly the rest of the season.
Griffin was cleared to practice November 16 and for contact two weeks later. Browns head coach Hue Jackson said a decision about his playing status would not be immediate, per Mary Kay Cabot of Cleveland.com.
"He's ready to go, and I'll make a decision about which way we're going as we go through the week," Jackson said. "Just because he's cleared doesn't mean we're just going to walk back out there and play. There's still practice and there are still things we need to do and see before I decide to stick him back out there."
Griffin expressed his excitement at being able to get back on the field when he was cleared for contact, per Cabot: "Beyond blessed to have an opportunity to get back on the field with my brothers. I promise my teammates and coaches to give them everything I have as we work to finish the season strong."
At 0-12, the Browns are in full evaluation mode, trying to determine who will be on their roster next season. They have had a difficult time keeping quarterbacks healthy in 2016, as Griffin, Cody Kessler and Josh McCown have all started games.
Kessler, who is a rookie, did show promise with six touchdowns, two interceptions and a completion percentage of 65.6 in eight games. He has suffered two concussions this season, though, which is a cause for concern in his long-term outlook.
With four games remaining this season, Griffin has a chance to put himself in the quarterback mix for 2017 if he finishes well. He is also auditioning for other teams that might be in the market for a quarterback next season, so there is a lot at stake starting with Sunday's game against the Bengals.