During the North American hard court Masters swing in March, Sousa started the Indian Wells Masters with a win over Aleksandr Nedovyesov, followed with a second-round loss to 20th seed Ernests Gulbis.During this run of losses, Sousa reached the semifinals of the Portugal Open's doubles competition and the third round at the 2014 French Open doubles competition, where he partnered with American Jack Sock and lost to Andrey Golubev and Sam Groth.He also became the highest ranked Portuguese ever, climbing from No. He won his first singles match against Janez Semrajc, but then lost in the doubles match and his second singles match against Blaž Kavčič.
Sousa is coached by former player Frederico Marques and practices at the BTT Tennis Academy in Barcelona. After winning national youth titles, he decided at the age of fifteen to invest in his career by moving to Barcelona.
After an unimpressive junior career, Sousa turned professional in 2008 and won his first singles tournament in 2009.
During 2009, Sousa was twice called to the Portugal Davis Cup team, winning both singles dead rubbers he took part in – over Philippos Tsangaridis from Cyprus in March and Algeria's Sid-Ali Akkal in July.
He also entered main draw events at the Barcelona Open (lost to Frederico Gil in the 2nd round) and the Croatia Open (lost to Matthias Bachinger in the 1st round).
Portugal won the tie 5–0 and progressed to the second round.
In September, Sousa joined Portugal's Davis Cup team to face Moldova in the semifinals of Europe/Africa Zone Group II.He won the first singles match over Lukáš Lacko but lost the doubles with Elias and his second singles match to Martin Kližan, meaning Portugal's relegation from Europe/Africa Zone Group I to Group II in 2013.Sousa started the 2013 season with his first participation in ATP tour level hardcourt tournaments at the Chennai Open and the Sydney International.At the Rosmalen Grass Court Championships, Sousa became the first Portuguese player ever to reach the semifinal of an ATP tour level grass tournament.He beat in succession Paolo Lorenzi, Mate Pavić and Thiemo de Bakker, In September, Sousa was selected to join Portugal Davis Cup team against Russia for the Europe/Africa's Group I Relegation Playoff.He progressed to a third round match-up with 6th seed Andy Murray, becoming the second Portuguese player to reach that stage. Sousa was then called for the Davis Cup team to face Morocco for the Europe/Africa Zone's Group II first round in early March.