Complex sentence: As Bonser continued to pitch in the minors without any further breakout seasons, his status as an elite prospect faded, but after a fast start at Rochester in in which he posted an ERA of 2.01, Bonser was promoted to the majors.
Split into simpler sentences: As Bonser continued to pitch in the minors without any further breakout seasons, his status as an elite prospect faded. But after a fast start at Rochester in in which he posted an ERA of 2.01, Bonser was promoted to the majors.