CHICAGO (CBS) — Michael Kopech might be ready to turn some heads when he makes his White Sox debut tomorrow, but he has his work cut out for him if he wants to make a bigger impression than a slightly older pitcher who donned black and white on the mound on the South Side this weekend.

Sister Mary Jo Sobieck stole the show on Saturday when she threw the ceremonial first pitch for Marian Catholic High School night, tossing a perfect strike from the pitching rubber to Lucas Giolito behind home plate.

It wasn’t just the impressive movement on her curve ball that wowed the crowd. Before making her pitch, Sobieck bounced the ball of her bicep back into her right hand.

The remarkable display might have astonished the crowd on the South Side, but it’s hardly a surprise.

Sobieck played softball in college, and practiced last week to prepare for her debut.