Fields (knee) wasn't spotted at practice Thursday, Rich Cimini of ESPN.com reports.
The same applies to Tyrod Taylor (groin), leaving Brady Cook and practice-squad member Adrian Martinez to handle the Jets' QB reps in Thursday's session. Friday's practice thus looms large in terms of the team's Week 15 signal-caller plans, but at this stage looming back-to-back 'DNPs' cloud the statuses of both Fields and Taylor.