CINCINNATI -- The latest setback in A.J. Green's recovery process will keep the Bengals wide receiver off the field indefinitely.

Green said he will likely not make his season debut Sunday against Baltimore after his left ankle did not respond well to workouts earlier this week. Following Monday's off-week practice, Green said he experienced swelling that derailed his plans of participating in Wednesday's practice. The ninth-year receiver said he doesn't know how long he will need to stay off the ankle as he continues the rehab process.

"For me, just gotta make sure I feel comfortable going out there and pushing it," Green said Thursday. "For me, just gotta make sure I gotta take care of me first before anything else."

Green has not played since he tore multiple ligaments in his left ankle during the Bengals' first practice of the preseason. He underwent surgery in late July. In recent weeks, he started to go through individual drills and was working toward being a full participant at practice.

On Monday, Green said he did more than he ever had during the recovery process as he ran routes and participated in multiple back-to-back drills. The ankle swelled in response, which forced him to rest.

"Right now, my ankle is saying it's too much," Green said. "That's when you gotta back off."

Green said the swelling wasn't as severe as it was a couple of weeks ago. The ninth-year receiver said he's still optimistic that he can play at some point in 2019 but wouldn't feel comfortable returning to the field without being able to go through a full practice.

"I just take it day-by-day," Green said. "If that comes to a point where I can't play, that's what's supposed to happen. Then my ankle's not where I need to be for me to play. Right now, I'm still thinking I still can play. I still can give this thing a little bit more time and then we go from there."