Complex sentence: Martínez started his career in the youth divisions of Olimpia and after playing two games for the reserve squad he was invited to join the first team squad by coach Gustavo Costas during the 2008 Apertura tournament.
Split into simpler sentences: Martínez started his career in the youth divisions of Olimpia. After playing two games for the reserve squad, he was invited to join the first team squad by coach Gustavo Costas during the 2008 Apertura tournament.