Middlesbrough striker Mido has been denied entry into Portugal meaning he cannot partake in the Algarve Cup.
Boro are in the Portuguese resort to take part in a four-team tournament which also features Celtic, Cardiff City and home side Vitoria Guimaraes.
Boro face Scottish champions Celtic on Tuesday evening as part of their pre-season preparations but the African marksman will not be involved.
The news is a blow to Mido who has returned to training hoping to make a big impact on Teesside this season.
"I would like Boro supporters to know why I am not in the team for the game in Portugal against Celtic," he said.
"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."