After playing a handful of snaps in the first half of Sunday's home game against the Cincinnati Bengals, Fields took over at quarterback in the third quarter for veteran Andy Dalton, who suffered a knee injury and is doubtful to return.
Dalton hurt the knee on a 14-yard scramble in the second quarter when he landed awkwardly on the Bears sideline. Dalton immediately pointed to Fields to enter the game and headed the blue injury tent where the medical staff examined him.
Dalton initially appeared to check out OK and later re-entered the game for a series before he went back to the locker room before halftime.
Dalton remained in uniform after halftime but did not have his helmet on the Bears' bench.
Fields ended the third quarter 4 of 8 for 55 yards and five rushing attempts for 24 yards.
Bears head coach Matt Nagy played Fields sparingly in the last week's season opener versus the Los Angeles Rams. The first-round pick played five snaps and scored a rushing touchdown in the losing effort.