Fields is believed to have bruised ribs, though he still has additional tests coming to evaluate him for more serious injuries, Ian Rapoport of NFL Network reports.
Bruised ribs would be a best-case scenario following the QB's early exit from a loss to Baltimore on Sunday. Even then, Fields would be in danger of missing time, especially with the Bears on a short week ahead of their Thanksgiving Day game in Detroit. If the rookie isn't ready, Andy Dalton will make his first start since Week 2.