This is fascinating. Thanks for the replies. Interesting that NF and Utrip apparently have a provision for a replacement, but ASA/USA does not.
I gotta ask--have any of you ever been forced to call an injured batter out in this situation? It seems it would be more likely to happen in ASA/USA and USSSA than NFHSA due to the fact that travel teams don't stack their rosters very deep. One of these days, we'll have a famous YouTube video of this scenario?