Because it doesn't work that way dummy. Spots for the individual events are filled, there are no substitutions like your football games.
And for the record, you are certainly aware that on Friday, the first day of training runs, she posted the 11th fastest time, aren't you? Then on Saturday, the last day of training runs, she posted the 3rd fastest time. All with a ruptured ACL.....
You didn't know that, did you? Of course not......
I could care less to be honest. You mean to tell me that there are no alternates at all? Sounds like a dumb a$$ system. What the hell are you talking about with the football game comment. You obviously know nothing about football (see, I can play your game too).