The 18-year-old has made a big impression in his first full season with the senior team, making 36 appearances in all competitions and scoring eight goals in the process.

Santos, who has four caps for Brazil’s under-20 side, is known for his ball-winning skills and ability to break up attacks.

Since Todd Boehly’s takeover of Chelsea in May, the club has signed a number of promising young players.

Boehly forked out £20million to sign England youth midfielder Carney Chukwuemeka from Aston Villa in the summer.

They’ve also signed teenagers Omari Hutchinson, Gabriel Slonina and Cesare Casadei from Arsenal, Chicago Fire and Inter Milan respectively.

Chelsea were in the race to sign highly rated Brazilian striker Endrick, however, the 16-year-old opted to join Real Madrid instead.