Umpire over ball

[jTheUmp]

I'd also guess it was due to offensive substitution... the U stands over the ball to give the defense a match-up opportunity.

The rule says that the defense must not delay in making their match-up substitutions; however, if the play clock expires during this match-up opportunity, it's a Delay-of-Game foul on the offense (they should've made their substitution earlier).

[bisonlj]

Originally Posted by jTheUmp

I'd also guess it was due to offensive substitution... the U stands over the ball to give the defense a match-up opportunity.

The rule says that the defense must not delay in making their match-up substitutions; however, if the play clock expires during this match-up opportunity, it's a Delay-of-Game foul on the offense (they should've made their substitution earlier).

Exactly correct. Teams in hurry-ups that try to sub after the ball has been placed do not like this but the rule was put in for a reason. Either get your subs in before the ball is getting placed or don't sub. These teams are usually not getting close to the play clock running out though.