I never noticed the play clock runs during substitutions until or game against ASU. One play when we were offense the ref is standing by the ball so the defense can substitute. We ended up having to burn a time out or getting a delay of game penalty because there was only a couple of seconds left on the play clock when we were allowed to snap. I feel like the play clock should stop at 10 during defensive substitutions so teams can't force their opponent to burn timeouts.