Complex sentence: He was drafted by the Pirates in the 15th round of the 1990 June draft, with the 390th overall pick, and having signed quickly, made his professional debut with the Pirates' affiliate in the Gulf Coast League that fall.
Split into simpler sentences: He was drafted by the Pirates in the 15th round of the 1990 June draft, with the 390th overall pick. After signing quickly, he made his professional debut with the Pirates' affiliate in the Gulf Coast League that fall.