Complex sentence: In 1987, at the age of 18, Lisbon-born Abel was invited to play for S.L. Benfica's youth teams, where he performed well winning many youth awards, moving to the first team after just one season.
Split into simpler sentences: In 1987, at the age of 18, Abel was invited to play for S.L. Benfica's youth teams. He performed well, winning many youth awards, and moved to the first team after just one season.