He wasn't on TV very much because QBs didn't throw his way.
I remember in one game against SDSU, the SDSU QB threw the ball in his direction one time. Gray covered an all-conference receiver that night and totally shut him down. The one pass that was thrown his way ended with Brian Gray running into the end zone with it for BYU's only TD of the game and the game winner.
Because TV angles suck, it's hard to see the work DBs do.