 Born in Barreiro, Carreira interested in basketball was sparked by a cousin, who took him to Barreirense, where he started competing at age 9.In 1997, he started his professional career in the basketball section of telecommunications company, Portugal Telecom, staying for one season, before moving to Seixal.After two seasons with the Seixal team, he returned to Portugal Telecom, where he won his first league title, and made his first cap for the national team.