AC Milan's upgrade of Thiago Silva's new contract is causing some tension inside the squad.The Brazil defender has enjoyed a bumper pay-hike after seeing PSG fail with a bid for him.But Corriere dello Sport says the developments haven't impressed Kevin-Prince Boateng. The Ghana ace is seeking a double your money deal, going from €2 million-a-year to €4 million-a-year.But Milan management have told Boateng to forget his demands - despite the terms still being €2 million-a-year less than Thiago Silva's new contract.Milan still need a big sale to balance the books, with Robinho the prime candidate to be sacrificed, though Boateng's frustration could also become a factor.