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 sentence lists roles along with the names of the individuals filling those roles. Using semicolons would help clarify the structure and separate the complex items in the list more clearly. The revised sentence would be:
"The captains of the high-school softball team are the pitcher: Marisa Martino; the outfielder: Rachel Morrison; and the catcher: Lisa Fiore."