At the age of 16, Ferreira completed a successful trial with FC Porto and was signed to the club's youth academy. Whilst in Portugal, he was loaned out to a second division team. At the age of 18, Ferreira thought it was time to return to Australia, and returned to Green Gully, his childhood club. Ferreira was then signed to Melbourne Victory's youth team playing in the National Youth League. He was a key player for two seasons, and was therefore promoted to the club's senior team.
On 10 May 2010, he was signed to a two-year professional contract with Victory.[3]
On 15 September 2010, Ferreira made his first start for Melbourne Victory against Wellington Phoenix, playing 81 minutes before being substituted for Matthew Foschini.
He scored his first A-League goal on 31 December, playing against Central Coast Mariners. Diogo scored a well placed goal in the 85th minute, in a 2–1 win for Melbourne.
Despite being a regularly used player at Melbourne Victory, Ferreira, along with teammates Tando Velaphi, Spase Dilevski and Sam Gallagher were released by Melbourne Victory in April 2013, shortly after the end of the 2012–13 A-League season.[4] He left the club, having made 52 out of a possible 84 appearances for the club.
Shortly after his release from the Victory, Ferreira went on trial with rival A-League club Brisbane Roar. Less than two months after his release from the Victory, Ferreira was signed by the Roar on a one-year deal, along with former Sydney FC attacking midfielder Dimitri Petratos.[5][6][7]
In January 2017, Ferreira signed a one-season deal with Penang FA.[10]
On 9 August 2017, Ferreira switched clubs and countries and signed for Indian club Mohun Bagan and became their fourth foreign signing of the season.[11] He was released on 16 December, with Ferreira claiming "personal issues" for the action.
International career
Ferreira has represented the Australia Olympic football team on seven occasions, scoring one goal. In addition to his Australian citizenship, Ferreira also has Portuguese citizenship and is eligible to play for Portugal.[12]