Manchester United failed in a loan deal for Real Madrid defender Fabio Coentrao after making a dramatic move late on Monday evening as the transfer window drew to a close.
The Premier League champions were able to wrap up a £27.5 million deal for Everton midfielder Marouane Fellaini just before the deadline passed but their paperwork was not completed in time to ratify the agreement.
It is thought that David Moyes's side agreed a season-long loan for the Portuguese international despite Madrid boss Carlo Ancelotti stating on Sunday that Coentrao would be staying at the Samtoagp Bernabeu.
However, complications have arisen due to the deadlines regarding paperwork submission with Fifa's Transfer Market System, with one or both clubs thought not to have ratified the deal with Fifa in time.
Tottenham were continually linked with Coentrao throughout the summer window as part of Gareth Bale's world-record move to Spain, but Andre Villas-Boas's side instead received an €100 million cash-only deal for the Welshman.
United missed out on a big-money move for Athletic Bilbao midfielder Ander Herrera after failing to meet the €36m release clause, capping a frustrating window for Moyes in which he has seen deals for Barcelona duo Thiago and Cesc Fabregas slip away.