The sentence that requires semicolons instead of commas is:
"The captains of the high-school softball team are pitcher, Marisa Martino, outfielder, Rachel Morrison, and catcher, Lisa Fiore."
This is because it contains multiple items that each have a description (role and name). Using semicolons helps clarify the separation between these complex items.
So, the correct version would be:
"The captains of the high-school softball team are pitcher: Marisa Martino; outfielder: Rachel Morrison; and catcher: Lisa Fiore."