The Hammers were on the brink of signing the 25-year-old holding midfielder last summer but the deal fell through after the relationship between the two clubs turned volatile.
Despite resolving their disagreements, Sporting have no plans of parting ways with the Euro 2016 winner.
"Forget [it]. He is not transferable in January," de Carvalho said told Portuguese newspaper Record.
"If one day he leaves, wherever it is, we must ensure that the footballing aspect of the decision is not called into question."