The Portuguese 'keeper's move is the subject of an appeal to Uefa.
General view - Stadium of Light Sunderland
On transfer deadline day Sunderland found themselves desperately trying to get hold of a new goalkeeper.
Pickford is a talent, but his youth makes him vulnerable. This was evident with his mistake v Southampton last weekend.
The search eventually took them to Portugal and a very late approach to sign Mika from Boavista.
In the end the deal did not get done in time, leaving Sunderland in something of a pickle.
Sunderland's Jordan Pickford
Now the player’s agent has gone into detail about why a deal did not get done in time.
Speaking to A Bola Cesar Bonaventura stated:
“The transfer of Mika was not validated because of an error in the computerised transfer system (TMS) which left pending the entries made by the clubs.
“At 22:30 the contract signed by Mika was sent to TMS.
“He’s a professional. His head is focused on Boavista.”
It was reported after the move collapsed that Sunderland had appealed to Uefa about giving them a pardon considering their technical issues. Any result of said appeal has not yet been disclosed or indeed reached.
If Sunderland do fail to bring in Mika, which is looking likely, the club will have to delve into the free agent market in order to fill the problem position during Mannone’s absence.