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.

It could take up to a week for a visa to be issued and Mido said: "I would like Boro supporters to know why I am not in the team for this evening's game in Portugal against Celtic.

"There have been ongoing problems regarding my visa, which I hope to have sorted shortly.

"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."