Benfica is seeking an increase in the release clause of Joao Felix. Felix currently has a €120 million ($136 million) release clause, but Benfica wants it to hit €200 million ($226 million). Felix has been compared to Cristiano Ronaldo.

Felix has been linked with Manchester United, Juventus, Barcelona and Real Madrid.

"Right now we are not interested in selling Joao Felix, and soon we will increase his release clause," Vieira told Tuttosport.

"He is one of the best products to have emerged from Portuguese football since Cristiano Ronaldo."