Chelsea are chasing Paraguayan teenager Mauro Caballero, according to The Mirror.
The 17-year-old has impressed for Libertad during the Copa Libertadores, the South American equivalent of the Champions League.
Valued at around £5m, the striker is also said to have caught the attention of Bayern Munich.
Caballero, whose father played 14 times for his country, has represented Paraguay Under-18s.