[5] Instead of returning to Slavia Prague, Musa was sent on a season-long loan to Portuguese Primeira Liga side Boavista on 25 August 2021, with an option to buy.

[5][8] He scored 12 goals and provided four assists, helping his side to a 12th place finish, as Boavista triggered Musa's buyout clause of €3.5 million.

[10] He made his debut for the club on 23 August, replacing Gonçalo Ramos in the 52nd minute in the 3–0 home win over Dynamo Kyiv in the second leg of the 2022–23 UEFA Champions League play-off round, helping his side qualify to the tournament.

[17] Musa started the 2023–24 season, on 9 August, closing the 2–0 victory over Porto in the Supertaça Cândido de Oliveira, winning his second trophy with Benfica.

[18] On 1 February 2024, Musa moved to Major League Soccer side FC Dallas, where he signed a four-year contract, with an option for a further year, as a Designated Player.

During stoppage time at the half, Musa scored his first goal for FC Dallas after a VAR check, with an assist from Bernard Kamungo, in the 1-2 loss.

[26] He made his senior international debut on 25 March 2023, replacing Marko Livaja in the 53rd minute of a 1–1 draw over Wales in the UEFA Euro 2024 qualifiers.