Porto are refusing to cave into Tottenham pressure to sell Ricardo Pereira.

Sky Sports says the Portugal right-back is Spurs' preferred choice to replace Kyle Walker, who joined Manchester City in a deal worth in excess of £50m this week.

Pereira has a release clause of £22m but Porto had previously indicated a willingness to negotiate a lower transfer fee for the 23-year-old because they needed to accrue funds.

Porto may accept an offer in the region of £16m, but another has said the club could hold out for the entire £22m release clause.

And Tottenham must decide if they are prepared to pay that much for a player who will initially act as second choice to Kieran Trippier.