Complex sentence: He made his breakthrough in the 1998--99 season, playing 27 league games and scoring three goals; in between, he served a loan stint at Benfica's feeder club F.C. Alverca, at the time also in the top level.
Split into simpler sentences: He made his breakthrough in the 1998--99 season, playing 27 league games and scoring three goals. In between, Leal served a loan stint at Benfica's feeder club, F.C. Alverca, at the time also in the top level.