[9] On 30 September 2020, Mancini made his senior debut for Vicenza, playing the first half of the Coppa Italia game against Pro Patria, which ended in a 3–2 win after extra time for his side.

[4][11] On 4 January 2021, the forward made his league debut, coming in as a substitute for Stefano Giacomelli at the 80th minute of the Serie B match against Brescia, which ended in a 3–0 away win for his team.

[14][15] In the following campaign, the forward saw his playing time limited by injuries and tactical decisions: in the end, he gained a total amount of nine senior appearances, as Vicenza eventually faced relegation from the second tier.

[26] The forward was included in the under-18 squad that took part in the 2022 Mediterranean Games in Oran,[25] as the Azzurrini eventually won the silver medal after losing to France (1–0) in the tournament's final match.

[4][11] Moreover, he has been regarded for his coordination, his off-the-ball movement and his finishing prowess, which provide him with a wide variety of options to find the net through, including acrobatic strikes and free kicks.