He started out at Danubio, being bought by Reggina in 2008. He went on to spend the vast majority of his professional career in Spain, in representation of several clubs, including Espanyol; he signed with Middlesbrough from England in 2015 and, two years later, joined Girona.
In January 2008, after scoring 19 goals in the 2007 Apertura with Danubio, Stuani was signed by Reggina in Italy, penning a four-year contract with the Serie A club.[3] He made his official debut on the 12th, playing 30 minutes in a 1–1 away draw against Empoli.[4]
When Stuani joined, the club was second from bottom and had the fewest goals scored in the league, following Rolando Bianchi's departure for Manchester City in the previous summer – he went scoreless in 12 games, but the Reggio Calabria team managed to retain their division status. In 2008–09, he scored his only league goal from a penalty kick in the last round, a 1–1 home draw against Siena,[5] having only appeared in four more matches during the entire season, which ended in top-flight relegation.
For 2010–11, Stuani remained in the country and on loan, but moved to La Liga with Levante.[9] He was used mostly as a backup to Felipe Caicedo,[10] but still contributed eight goals – second-best in the squad – as the Valencians easily retained their status, netting twice in a 3–1 home defeat of Málaga.[11]
In summer 2012, Stuani was linked with a move to Deportivo de La Coruña and even passed his medical[14] but, on 28 August, he signed a four-year contract with Espanyol[15] even though that club and Reggina had initially agreed on a season-long loan.[2]
On 15 July 2015, Middlesbrough reached an agreement for the transfer of Stuani,[17] with the deal being completed after receiving international clearance on 7 August, for a rumoured €3 million fee.[18] His first appearance in the Football League Championship occurred on 9 August, as he replaced Kike in the 77th minute of an eventual 0–0 away draw against Preston North End.[19] Three days later he made his first start, in the opening round of the League Cup, scoring in each half of a 3–1 win over Oldham Athletic at Boundary Park;[20] he scored a brace again in the second round on the 25th, as his team came from behind to win at Burton Albion.[21]
Stuani scored his first league goal on 29 August 2015, concluding a 3–1 victory at Sheffield Wednesday.[22] Seventeen days later, he netted twice in a victory of the same margin against Brentford at the Riverside Stadium.[23]
On 28 December 2015, Stuani finished Stewart Downing's cross in the 44th second for the only goal of the home game against Wednesday, putting Middlesbrough on top of the table.[24] He did not find the net again until the final game of the season on the following 7 May, opening a 1–1 home draw with Brighton & Hove Albion which won promotion to the Premier League at the opponents' expense; the goal's worth was valued at £170 million.[25]
On 21 August 2016, Stuani scored his first goals in the top division in his first game in the competition, grabbing a brace against Sunderland in a 2–1 win at the Stadium of Light.[26]
On 10 March 2019, Stuani became the club's all-time scorer in the top tier with 38 successful strikes after a 2–3 loss to Valencia at the Estadi Montilivi, surpassing former holder Jandro;[30] despite totalling 19 during the season to repeat the same position in the scoring department, the team succumbed to relegation on the last matchday.[31][32]
Subsequently, a number of clubs approached Stuani for a summer move, most notably champions Barcelona.[33][34] However, he eventually put pen to a contract extension with until 2023.[35] He missed the first two league games due to a groin injury,[36] but scored in his first appearance on 1 September 2019 to help the hosts defeat Málaga 1–0;[37] he added a hat-trick the following weekend, at home to Rayo Vallecano (3–1).[38]
Stuani was selected by manager Óscar Tabárez for the finals in Brazil.[42] He scored in both of Uruguay's warm-up matches for the tournament, the only goal of the game against Northern Ireland after coming on at half-time for Diego Forlán,[43] and the second in a 2–0 win over Slovenia.[44] He made his tournament debut on 14 June, starting in a 3–1 loss to Costa Rica in Fortaleza,[45] and added a further three bench appearances in a round-of-16 exit.
Stuani was named in Uruguay's squad the following year, as they attempted to defend their continental crown at the 2015 Copa América. He made two substitute appearances in Group B, in a quarter-final finish.
Stuani was included in the final 23-man squad for the 2018 World Cup in Russia.[46] His first match in the competition took place on 30 June, when he replaced Edinson Cavani (who had scored twice) for the final 16 minutes of the 2–1 round-of-16 victory over Portugal.[47] He started in the next match due to injury to the same teammate, and played 59 minutes in the 2–0 defeat against France.[48]
^"El Albacete se salva a lo grande" [Albacete save themselves in style]. Marca (in Spanish). 19 June 2010. Archived from the original on 7 April 2014. Retrieved 2 April 2014.
^"El Levante ficha a Stuani" [Levante sign Stuani] (in Spanish). Fichajes. 29 July 2010. Archived from the original on 7 April 2014. Retrieved 2 April 2014.
^"El Racing ficha a Stuani" [Racing sign Stuani]. Marca (in Spanish). 12 August 2011. Archived from the original on 7 April 2014. Retrieved 2 April 2014.
^Estepa, Javier (21 December 2011). "Todo por un penalti tonto" [All because of a foolish penalty]. Marca (in Spanish). Archived from the original on 6 June 2014. Retrieved 5 June 2014.
^"Principi d'acord per la sortida d'Stuani" [Agreement in principle for the departure of Stuani] (in Catalan). RCD Espanyol. 15 July 2015. Archived from the original on 16 July 2015. Retrieved 15 July 2015.
^Pérez, José I. (19 August 2017). "El ADN del Atlético no se ficha" [You can't sign Atlético's DNA]. Marca (in Spanish). Archived from the original on 9 February 2018. Retrieved 19 August 2017.
^Gracia, Albert (20 May 2018). "El gol en Girona se apellida Stuani" [Goal is named Stuani in Girona]. Sport (in Spanish). Archived from the original on 12 June 2018. Retrieved 4 June 2018.
^Biescas, Álex (8 September 2019). "A Stuani le da igual el rival o la categoría" [Stuani could not care less about opponent or tier]. Diario AS (in Spanish). Archived from the original on 16 September 2019. Retrieved 19 September 2019.
^"Uruguay ganó con goles de Salto" [Uruguay won with goals from Salto]. La Prensa (in Spanish). 15 November 2012. Archived from the original on 3 April 2018. Retrieved 3 April 2018.