After a loan from Tombense, a proxy club for the investees, Flu bought Mariano from Tombense outright. Mariano was chosen the best right back of the 2010 Campeonato Brasileiro Serie A by the Placar magazine. He was also selected to the Brazilian national football team on October 2010, and has been acclaimed as one of the most complete rightbacks of the Brazilian football. He has been called up by the Brazilian national football team 2 times, but both teams, he stayed on the bench.
Well known for his absurd speed and acceleration, he also has great accuracy at crossings, beyond of his great stamina and power of marking. Mariano is always one of the leaders of assists in Brazil, whether in the Fluminense's squad or among the Brazilian right backs.