It is not just West Ham that find Carvalho interesting but Everton now are looking into the player.
Everton are reported to be willing to open talks to the transfer of the 25-year-old for €35 million and Sporting may expect an increase in the bid since the release clause of the player amounts to €45 million.
But it looks like the club are not interested in selling Carvalho and is arranging a new deal that will run until 2021. If the playmaker agrees with the new contract, he will be given a pay increase with a bigger release clause.
The clause may go from €45 million to €60 million, which would allow for a bigger negotiation margin for the club and would make it more difficult for Everton, West Ham and other clubs to price the player.
William may not also be sold in January, but if Everton are really serious about getting the player, they may need to increase their bid especially if Carvalho signs the new deal.