Manchester United have confirmed the arrival of teenage defender Diego Leon from Cerro Porteno, for an initial fee of £3.3m that could rise to £7m.
United agreed the transfer back in January, but Leon was unable to make the move until he turned 18 in April.
The left-back, who has appeared for Paraguay's under-20 side on nine occasions, made 33 senior appearances for the 34-time Paraguayan champions.
In a statement, United said Leon "will be supported by our first team and the Academy whilst he settles into life in Manchester."
While Leon is expected to represent United's under-21 team, the potential exit of Tyrell Malacia could also see him serve as back-up to first-teamers Luke Shaw and Patrick Dorgu.
Leon is United's second signing of the transfer window, after they completed a £62.5m deal to acquire Matheus Cunha from Wolves in June.
They remain in talks to sign Bryan Mbeumo from Brentford for a similar price and have also been linked with Aston Villa's Ollie Watkins.
