CHICAGO -- Bears rookie quarterback Justin Fields was ruled out in the second half of Sunday's 16-13 loss to the Baltimore Ravens with an injury to his ribs.
Initial tests did not reveal any broken ribs, a source told ESPN's Adam Schefter. Fields will undergo further tests Monday.
Fields walked back to the locker room early in the third quarter after first being examined in the blue medical tent. It's unclear on which play he suffered the injury; the first-round draft pick was hit often by the Baltimore defense.