Complex sentence: In 2015, after logging a 7--1 record with a 3.15 ERA for the AAA Louisville Bats, he was promoted to the majors and made his major league debut on June 5 at the age of 23.
Split into simpler sentences: In 2015, after logging a 7--1 record with a 3.15 ERA for the AAA Louisville Bats, he was promoted to the majors. He made his major league debut on June 5, at the age of 23.