Manchester United's new Brazilian signing Anderson is facing work permit problems and may have to wait a year before he can play for the club.United agreed a deal with Porto in early June to sign the 19-year-old.
But Anderson does not have enough caps for Brazil to satisfy Home Office rules and his first application was refused.
United lodged an appeal on Thursday - with a verdict expected within 48 hours - but if that fails they cannot reapply until next year.
However, United are confident they will successfully be able to claim that Anderson is a special case because his age meant he had no chance of fulfilling the criteria.
They will also argue he will bring exceptional talent to the Premierl League.
Anderson needs to have played in 75% of Brazil's international fixtures in the previous two years to meet Home Office criteria.
The Premier League champion's solicitor, Maurice Watkins, asked the six-man panel to consider Anderson as a special case.
Anderson has described the proposed move to Old Trafford as "a dream come true".
He said: "I cannot wait to play in the same team as Cristiano Ronaldo, who is a great player, as well as Wayne Rooney and many more."
His move to United was announced at the same time as Sporting Lisbon youngster Nani, who as a Portuguese citizen has no work permit problems.
