The Foxes agreed a £22million deal with Sporting Lisbon for the Portugal international on transfer deadline day, however, Silva’s registration was rejected by FIFA after the paperwork arrived 14 seconds late.
Leicester could have to wait until January to have Silva available but they have appealed the case and are hoping to make him eligible for selection in the coming weeks.
Shakespeare has revealed that they should have a clearer picture on the situation in the next few days but admits it is all up in the air at present.
"Unfortunately it's still an ongoing process,” Shakespeare said.
"I'd love to be able to say he is available for selection but as I said from a football point of view we are awaiting the legal department so I have no further news for you on that, I'm sorry.
"I'm waiting for news, I'm waiting for an update and hopefully I will get that in the next 24-48 hours."