Leicester agreed terms with the Sporting player on deadline day, after seeing Danny Drinkwater leave for Chelsea.
However, in a bizarre development, it has been revealed that Leicester's and Sporting's documentation for the £22m move arrived on FIFA's computerised system an agonising 14 seconds after the deadline had passed.
Leicester requested a two-hour extension to Thursday's 11pm deadline in order to finalise all the necessary paperwork, but despite a series of setbacks, remained confident they could conclude a deal.
The two clubs are now trying to find a solution to the situation and will work with FIFA in an attempt to get the decision overturned. The former Premier League champions have submitted an appeal and Silva says he is willing to take the matter to the Court of Arbitration for Sport.
Worst case scenario, if football's governing body refuse the registration documents, Silva will return to Portugal and Leicester will pay no money for him.