Chelsea are likely to face stiff competition from Barcelona and Real Madrid for the signature of Paraguay starlet Mauro Caballero.
Owner Roman Abramovich is keen for the Stamford Bridge club to reduce the average age of its first-team squad and Caballero was reported to have caught the eye of the club's scouts last month.
However, the Libertad player's reputation has rocketed following a string of superb performances in the Copa Libertadores and the La Liga giants are now also tracking the 17-year-old, according to talkSPORT.
The player is said to be valued at around £5m.