Mosevich's career started with Argentinos Juniors.[2] He was an unused substitute in an Primera División match against Olimpo in November 2015, prior to making his professional league debut on 13 March 2016 versus Temperley.[2] By August 2017, Mosevich had made five appearances for Argentinos.[2][3] On 30 June 2018, Swiss Super League side FC St. Gallen completed the loan signing of Mosevich.[2] His first appearance arrived on 26 July, during a UEFA Europa League qualifying match with Sarpsborg 08.[2] Sixteen further appearances followed in all competitions as they placed sixth in the Super League.[2]
On 29 June 2019, a loan to Nacional of Portugal's LigaPro was agreed.[4][5] He didn't appear competitively until 10 November, featuring in a victory over Covilhã.[2] He went on to appear fourteen times, scoring his first senior goal in the process during a win against Farense on 7 December.[2] The club was promoted to the Primeira Liga after finishing in first place, though weren't officially deemed champions as the season was cut short due to the COVID-19 pandemic.[2] Mosevich soon returned to Argentina, before leaving on loan to Portuguese football again on 6 October 2020 as he agreed to terms with newly promoted LigaPro team Vizela.[6]
In January 2022, Mosevich moved to Patronato on a one-year loan deal [7] Ahead of the 2023 season, Mosevich joined Instituto on loan until the end of 2023.[8] The next season, he moved to Chile and joined on loan to O'Higgins.[9]