With Ghana in 2016
|Full name||Joseph Alfred Duncan|
|Date of birth||10 March 1993|
|Place of birth||Accra, Ghana|
|Height||1.81 m (5 ft 11 in)|
|Cagliari (on loan from Fiorentina)|
|2012–2014||→ Livorno (loan)||51||(1)|
|2015–2016||→ Sassuolo (loan)||33||(1)|
|2020||→ Fiorentina (loan)||13||(1)|
|2021–||→ Cagliari (loan)||16||(0)|
* Senior club appearances and goals counted for the domestic league only and correct as of 19:26, 9 May 2021 (UTC)|
‡ National team caps and goals correct as of 29 March 2021
Duncan began training with Inter Milan in the summer 2010. But due to FIFA regulations, he formally joined Inter in March 2011, after his 18th birthday. During that time, he lived in Inter training centre "Centro Sportivo Giacinto Facchetti" in Milan. Duncan made his Serie A debut for Inter on 26 August 2012, in a match against Pescara when he came on as a substitute in the 86th minute for teammate Walter Gargano.
On 19 July 2014, Inter agreed to loan Duncan to the fellow Serie A side Sampdoria for two seasons, until 30 June 2016. The club bought Duncan outright for about €3 million in January 2015. He signed a 4+1⁄2-year contract.
On 23 July 2015, Duncan was signed by Sassuolo on a temporary deal, with an obligation to sign him outright at the end of season from Sampdoria, for about €6 million. On 6 March 2016, Duncan scored his first goal for the club against A.C. Milan in a 2–0 win.
On 31 January 2020, Duncan joined Fiorentina on loan with an obligation to buy.
On 17 January 2021, Duncan joined Cagliari on loan until 30 June 2021 with an option to buy.
|Inter Milan||2012–13||Serie A||3||0||1||0||—||—||4||0|
|Livorno (loan)||2012–13||Serie B||19||1||0||0||—||4||1||23||2|
|Fiorentina (loan)||2019–20||Serie A||13||1||0||0||—||—||13||1|
|Cagliari (loan)||2020–21||Serie A||16||0||—||—||—||16||0|
- Inter Profile
- Game report by ESPN
- "Ufficiale: Joseph Alfred Duncan Blucerchiato per Due Stagioni" [Official: Joseph Alfred Duncan Sampdoria for two seasons] (Press release) (in Italian). U.C. Sampdoria. 19 July 2014. Archived from the original on 2014-07-22.
- F.C. Internazionale Milano S.p.A. bilancio al 2015-06-30 (statutory filing) (in Italian). Milan: Italian C.C.I.A.A. 2015.
- U.C. Sampdoria S.p.A. bilancio al 2015-12-31 (statutory filing) (in Italian). Genoa: Italian C.C.I.A.A. 2016.
- "Duncan sar blucerchiato il centrocampista al Doria fino al 2019" (Press release) (in Italian). Genoa: U.C. Sampdoria. 31 January 2015. Retrieved 27 December 2015.
- U.S. Sassuolo S.r.l. S.p.A. bilancio al 2015-12-31 (statutory filing) (in Italian). Modena: Italian C.C.I.A.A. 2016.
- "Calciomercato: acquisito dalla Sampdoria il centrocampista Alfred Duncan" (in Italian). U.S. Sassuolo Calcio. 23 July 2015. Archived from the original on 24 September 2015. Retrieved 27 December 2015.
- "UFFICIALE: Fiorentina, ecco Duncan: prestito con obbligo di riscatto". Retrieved 31 January 2020.
- "UFFICIALE: Cagliari, dalla Fiorentina arriva Duncan in prestito con diritto di riscatto".
- "Alfred Duncan". Soccerway. Retrieved 25 October 2020.
- FIFA U-20 World Cup Turkey at FIFA.com, retrieved 30-1-2017