Having previously represented Defensor Sporting at various youth levels, with whom he won the U17 Clausura title in 2016, Boselli received his first experience with the senior team on 2 February 2017 when he featured as an unused substitute in a 2–0 win over Rampla.[2][3] He made his debut later that month, replacing goalscorer Gonzalo Bueno in the second half of a 2–1 victory against Juventud.[4]
On 13 August 2019, Club Athletico Paranaense confirmed that Boselli had joined the club on loan until December 2020.[6] However, he left the club again less than a month later, even before making his debut. It was later revealed by the club's manager, Tiago Nunes, that Boselli "did not come to play in the first team" and that he "came to take the official photo with the black and red shirt but was immediately transferred to the U23 squad".[7] He then began training with América Futebol Clube (MG) and even played a friendly game for the club, before joining the club on 5 September 2019 on loan for the rest of 2019 to guarantee more minutes on the court.[8] However, he would return to Club Athletico Paranaense for the 2020 season, as the loan deal with the club was valid until December 2020. Boselli was registered for Paranaense's U-23 squad.[9]
Loan to Cádiz B
In September 2020, Boselli began training with Cádiz CF B. The deal was announced on 5 October 2020, signing a loan-deal until 30 June 2022.[10] The loan was terminated early after the 2021–22 season.
Loan to Tondela
On 30 August 2021, Boselli joined Tondela in the Portuguese Primeira Liga on loan until June 2023.[11]
Gil Vicente
On 15 July 2022, Primeira Liga side Gil Vicente announced the signing of Boselli on a three-year contract.[12]
^"Juan Boselli assina por três épocas" [Juan Boselli signs for three seasons] (in European Portuguese). Gil Vicente FC. 15 July 2022. Retrieved 10 September 2023.
^"Хуан Боселли – в "Пари НН"" [Juan Boselli - in Paris NN] (in Russian). FCNN. 10 September 2023. Retrieved 10 September 2023.
