Stoke City are following Peterborough United defender Ricardo Santos.
Lisbon media sources say Potters boss Mark Hughes has had the young stopper scouted in the opening weeks of this season.
Posh signed Portuguese defender Santos on a three-and-a-half-year contract in February.
Santos arrived on a free transfer from Thurrock, having played 24 times this term in Ryman League North.
A former Dagenham & Redbridge youth player, the 18-year-old, 6ft 5ins centre-half started the campaign with Dover Athletic.
