Manchester City have been told they will have to pay £20million to sign goalkeeper Willy Caballero in the January transfer window. City are believed to be the market for a new shot-stopper in the new year, with Manuel Pellegrini losing faith with the under-fire Joe Hart. Celtic’s Fraser Forster and the Galatasaray ace Fernando Muslera have both been linked with moves to the Etihad, but Pellegrini is said to favour signing Caballero from former club Malaga. However, despite the interest, Malaga say they would only part with the goalie if City made a bid which matched his £20million release clause. ‘We will not sell Willy Caballero,’ said Malaga director general Vicente Casado. ‘He will not leave unless someone pays his release clause and he is in agreement. At the moment we are focused on building the squad’ Caballero only signed a new contract with Malaga recently, but his excellent performances in recent weeks have seen a number of top European sides show an interest.