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 needs semicolons because it lists multiple items (positions and names) that contain internal commas, which can lead to confusion. Using semicolons will help clarify the different roles and names in the list.
Corrected version with semicolons: "The captains of the high-school softball team are pitcher; Marisa Martino; outfielder; Rachel Morrison; and catcher; Lisa Fiore."