ENGLEWOOD, Colo. -- Denver Broncos rookie quarterback Drew Lock said Thursday he's not sure when he will be able to throw a football again, and coach Vic Fangio said it's possible Lock could at least open the season on injured reserve.
Lock suffered a severely sprained right thumb -- his throwing hand -- early in the third quarter of Monday night's preseason loss to the San Francisco 49ers. He underwent an MRI exam Tuesday and a sprain was confirmed.
X-rays taken at the stadium Monday night were negative.
Lock will neither play nor practice for the remainder of the preseason and will be limited to conditioning work only.