The NFL moved the umpire out of the middle because they were losing too many umpires to injury. Players would use the umpire as a screen, players would run into the umpire, and it would only take one person landing on the umpire wrong for him to have to go the hospital. The NFL decided to limit the damage to its officials and have the umpire in the offensive backfiled unless the offense was attempting a scoring kick or in the last two minutes of each half, when the ball needs to be spotted quickly.