Williams was taken off the field on a stretcher in the first quarter after taking a helmet-to-helmet hit from Barnett. The Packers announced the tailback is being evaluated for head and neck injuries, and he has feeling and movement in all of his extremities.
The third-year pro was transported via ambulance to a local hospital for further evaluation, according to Thursday night's broadcast.
Williams was injured on the Packers' first play of the game, which was a screen pass. The running back was stood up at the line of scrimmage by a group of Eagles defenders when Barnett arrived late and appeared to deliver a helmet-to-helmet hit on Williams after officials had blown the play dead.
Williams raised his left arm and gave a thumbs-up to the Lambeau Field crowd as he was taken to the locker room. Barnett was penalized for unnecessary roughness on the play, but was not ejected.
The Eagles held a 21-20 halftime lead over the Packers.