If Quinton Carter is the type of player who's looking for signs, the ear-shattering thunderclap  that sounded as John Fox was about to read his name in the injury report could be a bit disturbing -- or, perhaps, empowering.


Fox had only uttered, "Did not participate today" when thunder, apparently from a lightning strike within a mile of the Broncos' headquarters, interrupted him and startled the two dozen reporters crowded around him.


The news wasn't good regarding Carter after Fox resumed his report; the second-year safety now has a knee problem to go along with the hamstring injury he suffered during practice July 27.


Carter hasn't been on the field since then and was one of three Broncos not to practice Wednesday, joining RT Orlando Franklin (concussion) and CB Joshua Moore (right hamstring).


Denver practiced nearly four hours earlier than expected because of a stormy forecast for the afternoon. As a result, the rescheduled practice was closed to the public, disappointing the 4,000 fans who had been expected at Broncos headquarters for the session.


For up-to-the-minute Broncos updates, follow Andrew Mason on Twitter at @CBSSportsNFLDENand @MaxBroncos.