Leicester's £22m summer signing Adrien Silva will not be able to make his Premier League debut until January after football governing body Fifa rejected a Football Association appeal to authorise the transfer.
The Foxes completed the deal for the Portuguese midfielder 14 seconds after the transfer window deadline on 31 August, prompting Fifa to withhold the international transfer certificate required for his registration.
And Fifa has held firm to its initial stance in spite of an FA appeal to its Players' Status Committee.
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Leicester, who have endured a difficult start to the season and currently hover just one place above the relegation zone, will only be able to register and then play Silva once the transfer window reopens in January.
The 28-year-old, signed as a last minute replacement for Danny Drinkwater who was sold to Chelsea on deadline day for £35m, has trained on his own with fitness coaches and spent time back in Portugal.
For an international transfer to be ratified, two two clubs involved must enter the key details into Fifa's TMS before their association's deadline — 11pm in England.
If the information matches, an international transfer certificate (ITC) will be issued giving the deal the green light.