Complex sentence: Maxime Lopez is a product of Marseille's football academy, having joined "l'OM" in 2010 from F.C. Burel, and represented the club at U- 19 level in the UEFA Youth League.
Split into simpler sentences: Maxime Lopez is a product of Marseille's football academy, having joined "l'OM" in 2010 from F.C. Burel. During his time in the academy he represented the club at U- 19 level in the UEFA Youth League.