The Bills' medical staff has not cleared to him practice, so Ryan is adhering to that recommendation.
"I just met with Sammy and he feels fantastic, but we're going to be smart with this and we'll do what's best for him," said Ryan.
"Until all our medical people are on board with him coming back out there on the field, then we're not going to practice him. When that times occurs, and hopefully that will occur soon, he'll be back out there. He feels great so hopefully that's a positive sign."
It was assumed Watkins would practice this week and be ready to play against Jacksonville on Nov. 27 when he was eligible to do so, but that timetable may now be pushed back.
Thus, the Bills may need to rely more on newly-signed Percy Harvin who made his season debut in Seattle and played 21 snaps without getting a touch or a target.
"He wasn't able to run a full route complement; we never felt that he was really ready to do that football shape wise, but we feel better about it moving forward," said Ryan. "Percy won't just be a decoy for us."