Chelsea have confirmed the signing of 19-year-old defender Aaron Anselmino from Boca Juniors for a reported £15.6m transfer fee.
Anselmino, who made 10 appearances for Boca in all competitions last season, has signed a seven-year deal but will return to Argentina on loan for the 2024-25 season.
The central defender scored once in their Copa Sudamericana triumph over Trinidense in April, but struggled for much of the campaign with injury.
Anselmino becomes Chelsea's fourth teenage signing of the transfer window following the arrivals of Marc Giui (18), Caleb Wiley (19) and Omari Kellyman (19).
Enzo Maresca has now welcomed eight new faces through the doors of Stamford Bridge, with Atletico Madrid's Samu Omorodion also linked with a move to the Blues.
Chelsea conclude their pre-season preparations this weekend in SW6 against Inter before taking on Manchester City in their opening game of the Premier League season.