Coming from the youth system at UD Las Palmas, Mujica came to FC Barcelona to join the U12 squad. When he was with the U19A squad, he made his debut for B squad, scoring a goal against Sabadell. For the 2016/17 season he became an official member of the B squad.
Mujica is a tall striker but also a mobile one and one who can create space with his movement. Despite being a forward, he works hard in defence and is often the first to put pressure on the opposing defence.