CHICAGO -- After being added to the injury report because of an illness, Ravens quarterback Lamar Jackson is "50-50" for Sunday's game at the Bears, a source told ESPN's Adam Schefter.

Several Ravens players were affected by a cold that swept through their building last week, including Jackson, wide receiver Rashod Bateman and center Bradley Bozeman, among others, a source told Schefter.

Jackson, who is listed as questionable, was added to the report as a precautionary measure because he wasn't feeling 100%, a source said. Jackson does not have COVID-19, according to a source.

The Ravens also downgraded wide receiver Marquise Brown to out with a thigh injury. He had missed two practices this week before being limited Friday.

Jackson returned for a full practice Friday after missing two days with an illness. He did not carry an injury designation after Friday's practice and said with a big smile that he was "feeling great."

Jackson has missed only two games in his four-year NFL career. He sat out the 2019 season finale because Baltimore had already secured the No. 1 seed and was held out of a Week 12 game in 2020 after testing positive for COVID-19.

Tyler Huntley, who is the Ravens' primary backup, has never started an NFL game. Baltimore elevated quarterback Trace McSorley from the practice squad. He would back up Huntley if Jackson can't play.

The AFC North-leading Ravens (6-3) are coming off a 22-10 loss at the Miami Dolphins, scoring their fewest points with Jackson as a starter. After Sunday's matchup with the Bears, Baltimore doesn't play another team with a losing record for the final seven games.