Chelsea reportedly had an offer for Luisao rejected by Benfica on transfer deadline day.
Manager Jose Mourinho made no secret of his desire to sign a centre-back during the summer window, with Everton's John Stones his major target.
However, having had numerous bids for the England international turned down, Mourinho switched his attention elsewhere, before Michael Hector and Papy Djilobodji were both signed on Tuesday.
Yet, according to Portuguese publication O Jogo, the Blues also had an approach for 34-year-old Luisao rebuffed by his club.
The report adds that Benfica informed their Premier League counterparts that they would have to pay the defender's £14m release clause to conclude the deal.
