The 25-year-old Egypt international was unable to travel to the Algarve with the rest of his team-mates because of a problem with paperwork.

Mido said: "I would like Boro supporters to know there have been ongoing problems regarding my visa, which I hope to have sorted shortly."

He added: "It could be that the Portuguese embassy require up to a week to amend this situation, thus preventing my ability to travel to Portugal in the very immediate future."

Boro have spent the last few days trying to resolve the matter to allow the former Tottenham frontman to meet up with manager Gareth Southgate and his squad.

But it could take up to a week for a visa to be issued, which is a major disappointment for a player who returned for pre-season training in good shape after spending several weeks working with fitness coach Nick Allamby in his home city of Cairo following an injury-hit first campaign on Teesside.