The Portuguese press has reported that Chelsea are interested in Atletico Madrid central defender Jose Ze Castro.
The 23-year-old is regarded as a promising new talent and reports in Portuguese newspaper Record say that Atletico have rejected an offer from Blues boss Jose Mourinho in recent weeks but the Spanish club have not reacted to the story.
Ze Castro moved to La Liga in summer 2006 and is contracted to Atletico until June 2011.
He has represented Portugal at both U20 and U21 level.