After a season on loan with French sideLyon, he transferred across London toWest Ham United in 2022, where he became the only player to have won all four European Continental competitions after winning theUEFA Europa Conference League in his first season.[3]
Internationally, Emerson played for his native Brazil atunder-17 level, but he later declared his desire to represent Italy, having been grantedItalian citizenship in 2017. He has since represented the Italy national team, making his senior international debut with the side in 2018 and later taking part atUEFA Euro 2020, winning the tournament.
Born inSantos, São Paulo, Emerson played inSantos' youth team making his first team debut on 17 April 2011, coming on as a latesubstitute forKeirrison in a 3–0Campeonato Paulista home win againstPaulista. His first start occurred on 21 January 2012, in a 1–1 away draw againstXV de Piracicaba.[4] In February, he returned to the youth team,[5] but he was called up to the match againstMogi Mirim in the following month.[6] He also appeared againstItuano andPaulista, as the club was crowned champions ofPaulistão for the third consecutive time.
On 17 June, Emerson made hisSérie A debut, in a 0–1 defeat againstFlamengo.[7] He scored his first goal on 5 September 2013, but in a 1–2 loss atAtlético Paranaense.
On 25 August 2014, Emerson was loaned toSerie A'sPalermo, with a buyout clause.[8] He made his debut in the competition on 24 September, coming on as a second halfsubstitute forFabio Daprelà in a 3–3 away draw againstNapoli.[9] Emerson played nine league matches for the club, being mainly a backup to another new signing,Achraf Lazaar.
On 31 August 2015, Emerson joined fellow league teamRoma, on loan for one year.[10] A second-choice behindLucas Digne, he made his debut for the club on 4 October in a 4–2 away win against former side Palermo.
Emerson scored his first goal in the top league of Italian football on 14 May 2016, in a 3–1 away win againstMilan; after replacingStephan El Shaarawy in the 78th minute, he netted his team's third after a rebound.[11] His loan was extended for a further season on 7 July.[12]
On 5 December 2016, after reaching 12 matches duringthe campaign, Emerson was bought outright for a reported fee of €2 million.[13]
Emerson missed much of the first half of the2017–18 season due to ananterior cruciate ligament injury that he suffered in May 2017.[14] He made his comeback on 1 December 2017, coming off the bench in the last 15 minutes of the match againstSPAL for the Serie A, which turned out as his sole appearance for Roma during that season.[15]
On 30 January 2018, Emerson joined English sideChelsea on a four-and-a-half-year deal for an undisclosed fee.[16] According to Roma, the transfer fee was €20 million plus €9 million bonus.[17] He made his debut againstHull City in the fifth round of theFA Cup, assisting fellow January signingOlivier Giroud for his first Chelsea goal. The Blues came out 4–0 winners atStamford Bridge.[18]
Emerson made hisPremier League debut on 4 March 2018 as a second-half substitute in a 1–0 defeat atManchester City.[19] His first Premier League start came away toBurnley on 19 April. Emerson set upVictor Moses for the winning goal as Chelsea claimed a 2–1 victory.[20] Chelsea went on to win the2017–18 FA Cup but Emerson was injured and missed thefinal.[21]
On 26 September 2018, in his first appearance of the2018–19 season, Emerson scored his first goal for Chelsea, the equaliser in an eventual 2–1 away win againstLiverpool, in the third round of theEFL Cup.[22] On 24 February 2019, he started for Chelsea in the2019 EFL Cup Final on, and was one of the three Chelsea players to convert their spot kicks in the resulting shoot-out following a 0–0 draw after extra-time; however, Manchester City ultimately prevailed 4–3.[23] On 29 May, he assistedOlivier Giroud's opening goal in a 4–1 win overArsenal in the2019 UEFA Europa League Final.[24] On 17 March 2021, Emerson scored his firstUEFA Champions League goal for the Blues in a 2–0 home win overAtlético Madrid in the second leg of theRound of 16 tie.[25] Emerson was part of the Chelsea squad which won the2021 UEFA Champions League Final 1–0 againstManchester City, however did not come off the bench in the match.[26]
In March 2017, after being close to acquiring Italian citizenship, Emerson was reportedly pursued byItaly head coachGian Piero Ventura with the intention of switching his international allegiance to Italy.[34] He officially switched allegiance to Italy on 29 March 2017.[35] Emerson was called up by Ventura for matches againstUruguay andLiechtenstein in June 2017, however, withdrew due to injury and replaced byAndrea Conti.[36]
On 19 May 2018, new Italy coachRoberto Mancini called Emerson for Italy's May and June friendly matches againstSaudi Arabia,France and theNetherlands,[37] however, he withdrew due to another injury.[38] He was later called up again to the team in September 2018, for Italy's openingUEFA Nations League matches againstPoland andPortugal later that month.[39] He made his senior international debut for Italy on 10 September, during theUEFA Nations League match against Portugal, coming on as a second-half substitute forDomenico Criscito in his team's 1–0 away loss.[40][41]
Emerson usually plays as a left-back, and is known for his stamina, athleticism, physical qualities, and technique, which make him an effective offensive asset. He is also known for his ability to get past opponents and providecrosses into the penalty box. A versatile player, he is also capable of playing as awing-back orwide midfielder on the left flank, and has even been used in a more advanced role as an offensivewinger on occasion. Emerson's Chelsea profile notes that he is "skilful, possesses a good range of passing and reads the game well".[44][45][46][47][48]
Emerson has Italian ancestry on his mother's side fromRossano, nearCosenza in Calabria,[49][50] and has been an Italian citizen since March 2017.[35] His older brother,Giovanni, is also a footballer and a left back.[51]