Complex sentence: In the fifth inning, Royals player Raúl Adalberto Mondesí made his Major League Baseball debut, pinch hitting for Danny Duffy, becoming the first player to ever make their MLB debut in the World Series.
Split into simpler sentences: In the fifth inning, Royals player Raúl Adalberto Mondesí made his Major League Baseball debut, pinch hitting for Danny Duffy. Mondesí became the first player to ever make their MLB debut in the World Series.