Dias was born on 7 January 1991 in Covilhã, Portugal. At the age of six months, his family moved to France after his father, Quim Brito, a football player, signed with FC 4 Rivières 70, an amateur club located in Dampierre-sur-Salon in the Franche-Comtéregion. Dias began his football career playing for 4 Rivières at the age of five in 1996. He spent seven yearsat the club and, in 2003, signed youth papers with professional club Sochaux.
Sochaux
Upon his arrival to the club, Dias was inserted into the club's youth academy. He quickly rose through the ranks of the academy and established himself as one of the club's top prospects in his age group alongside fellow midfielderSerdar Gürler, strikerCédric Bakambu, and goalkeeperPierrick Cros. In the 2008–09 season, Dias began appearing with the club's reserve team in the Championnat de France amateur. He made his amateur debut on 29 November 2008 in a league match against Colmar appearing as a substitute. Dias finished the campaign with eight appearances; seven of them as a substitute. During the 2009–10 season, Dias continued to developed with the club's reserve team in the fourth division. He appeared in 15 matches scoring six goals. Also during the season, Dias was a part of the Sochaux under-19 team that reached the final of the Coupe Gambardella, the country's prestigious youth cup competition. In the lead up to the final, he scored doubles against Toulouse and Nantes in the quarter-finals and semi-finals, respectively. In the final match against Metz at the Stade de France, Sochaux were defeated 4–3 on penalties. Dias converted his penalty, however, early failed attempts by Gürler and Clément Giraud dashed the team's hopes. It was later reported by the media that scouts of English club Tottenham Hotspur attended the game to watch Dias. Midway through the 2009–10 Ligue 1 season, Dias, alongside Gürler, began integrating with the first team after managerFrancis Gillot announced his desire to give the club's youth talent an opportunity. On 7 April 2010, he made his professional debut in a league match against Marseille. Dias appeared as a substitute in the match and played 16 minutes in a 3–0 defeat. Two weeks later, he made another league appearance, again as a substitute in another 3–0 defeat, this time against Boulogne. Following the season, Dias spent the summer training with Portuguese Liga club Benfica. Benfica wanted the player to remain at the club, however, due to being under contract with Sochaux, he returned to France for pre-season training. On 2 September 2010, Dias signed his first professional contract agreeing to a three-year deal with Sochaux until June 2013. He was officially promoted to the senior team and assigned the number 28 shirt. Dias, however, still remains a fixture on the club's reserve team in the CFA having scored four goals in 10 appearances. His first professional appearance of the season came on 16 October in a 2–0 defeat to Montpellier. In January 2014, Dias was loaned out in Ligue 2 to AC Arles-Avignon, to gain more playing time.
International
Though Dias was born in Portugal, due to living in France since he was six months old, he acquired citizenship, thus making him eligible to represent both Portugal and France at international level. At the age of 14, Dias represented France at under-15 level. The following year, he was called up to the under-16 team by coach Francis Smerecki. Dias appeared in two friendly matches against Poland in March 2007. Between 2007–2010, Dias was not selected by Smerecki for international duty. In 2010, Dias announced his intent to represent Portugal at international level and confirmed his decision by declining the opportunity to attend a training camp for future France national under-21 players. He was later selected by the Portugal under-20 team. On 7 October 2010, Dias made his debut with the under-20 team in a friendly match against France. The following month, he was called up to the team against to participate in training sessions with the team preparing for the 2011 FIFA U-20 World Cup.
