Complex sentence: He went on to establish himself as an important offensive element, whether as a starter or from the bench--in his last season he scored six goals in 32 games, helping the capital side finish ninth after having promoted from the second level the previous season.
Split into simpler sentences: He went on to establish himself as an important offensive element, whether as a starter or from the bench. In his last season he scored six goals in 32 games, helping the capital side to finish 9th after having promoted the previous season.