Complex sentence: He pitched two years for the Boston Red Sox, going 16-14 over two seasons as the number two starter behind Pedro Martinez, however his ERA was 5.64 and he was clearly finished as the brilliant pitcher who dazzled fans and batters in 1991.
Split into simpler sentences: He pitched two years for the Boston Red Sox and was the number two starter behind Pedro Martinez. But he was finished as the brilliant pitcher who dazzled fans and batters in 1991.