Yes, the word "fatigue" has been used if that's considered discussion. Regardless, I don't understand it, and I won't until it's really explained to me. Just because it's hard for me to believe, doesn't mean I'm saying they're wrong.
Consider this: how many football teams in CFB or the NFL have one kicker to do all of the extra points, field goals, kick offs and punting ?
Very few.
Siebert hinted of fatigue late in the 2015 season, his freshman year. He did the same last year.
Fatigue for a kicker is both both mental and physical. A game's result can be lost by a missed field goal, or a short kickoff or a shanked punt and even a missed extra point. As a result, a kicking specialist who loses his confidence, on top of being fatigued, is a major problem.