Paul Dehner Jr. of the Cincinnati Enquirer reported Ross was going to be sidelined for the 2017 regular-season opener Sunday.
Ross sprained his knee during the Bengals' preseason finale against the Indianapolis Colts on Aug. 31. The team listed him as questionable for Week 1 on its injury report after he was a limited participant in practice Thursday and Friday.
Knee injuries have been a problem for Ross dating back to his time at the University of Washington. He had lingering knee problems as a sophomore during the 2014 season and missed the entire 2015 campaign after tearing his ACL during spring practice.
Ross also had surgery on his shoulder to repair a torn labrum after the NFL Scouting Combine in Indianapolis. The 21-year-old is a dynamic playmaker with big-play potential after posting 1,150 yards and 17 receiving touchdowns in 2016 at Washington.
Because of Ross' injury history, the Bengals had to be extra cautious with their first-year wideout to make sure he wasn't going to risk doing further damage.
Cincinnati's offense is still equipped to be explosive against the Ravens, with Green, Eifert and Brandon LaFell all proven pass-catchers for quarterback Andy Dalton.
Injuries were one of the reasons Cincinnati's win total went from 12 in 2015 to six last season. Green, Eifert and running back Giovani Bernard missed a combined 20 games in 2016.
If the Bengals want to get back in playoff contention this season, they need all of their playmakers operating at the top of their games. Ross figures to play a prominent role in the offense when he's healthy enough to get on the field.