A report in Portugal claims west-London based outfit are studying ways to entice the Uruguayan defender, but they may need to recalculate their estimations
Record reports that Andres Villas-Boas is working to entice his former club into accepting a bid for the 25-year-old who has a €30m release clause.
The Chelsea tactician, who led Porto to a treble triumph last term, is believed to have been given the go-ahead to offer cash and a player from the squad in exchange for Pereira.
However, a Porto source revealed they had not received an offer for the Uruguay international, and maintained it would cost interested clubs a €30m fee to sign him.
Just days ago the player's agent said his client was happy at Porto, but admitted a number of clubs had expressed an interest over the summer.
Pereira's contract with the Portuguese champions expires in 2015.