League sources told ESPN and the NFL Network on Sunday that Green is expected to miss six to eight weeks due to the injury. An MRI revealed the pass-catcher suffered a sprain along with torn ligaments in his left ankle, according to ESPN.
Green will get a second opinion on the injury that he sustained Saturday night, according to the NFL Network. He will not undergo surgery for now, but he will receive additional information before deciding how to approach the injury.
The star wideout suffered the ankle injury when he went against cornerback Dre Kirkpatrick for a pass thrown by Andy Dalton. Green and Kirkpatrick both fell to the ground while attempting to catch the football, according to the Cincinnati Enquirer.
The Bengals were practicing at Welcome Stadium in Dayton, Ohio. Cincinnati receiver Tyler Boyd said the field conditions at the venue were "terrible."
"The turf was terrible. I couldn't run any routes out there," Boyd said. "I'm falling all over the ground. It was bad. It was rocks, pebbles out there. Man, it was somewhere we shouldn't have been. I'm not trying to say any excuses, but it is what it is."
Bengals head coach Zac Taylor said the field quality at Welcome Stadium shouldn't be blamed for Green's ankle injury.
"I don't think the turf had anything to do with it," Taylor said Sunday after practice.
Green, a seven-time Pro Bowl selection, missed seven games last season due to a right toe injury. The 31-year-old receiver missed only four contests during his first five seasons in the NFL, but he has missed 13 games in the last three campaigns.