Ryan said that a decision will be made very late as to whether he plays, but the coach has been encouraged by Cromartie's improvement in recent days.
"I feel good about his progress," he told the Jets' official website. "But again, the big thing is I'm not saying he's going to play, doctors make that determination and quite honestly, that decision is not made until game day.
"A guy can look good and all that stuff, but really that final decision whether the young man plays or not is actually game day. So that protocol for concussions now, it can go all the way right up to a game-time decision.
"Again, I'm not saying he's going to play or whatever. I know he seems to be doing pretty well. Today he was out there, like I said, in the red jersey but he was able to move around and things so that was good."
The Jets are 6-7 so far this season.