The beginning of his career was playing for the city of Pimenta in 2007. At the end of the same year he was selected to play for Minas Tênis Clube. He began his career at the traditional club in March of 2008, at the age of 14. Flavio was part of all Brazilian national teams from under 19 to under 23. In 2010, he began the sequence of important results being silver medalist in the South American Under 19 Championship and was elected the best middle blocker. In 2012, South American Under 21 champion and also best middle blocker of the championship. In 2013, Flávio was silver medalist in the FIVB Under 21 Championship, the following year, South American champion under-23 and best middle blocker, in 2015, champion of the Pan American Cup and best middle blocker, besides being runner-up of the Pan American Games with the main national team. In 2018, he was silver medalist in the Pan American Cup and was elected the best middle blocker.