Brazil are insisting on his release for the Under-23 squad which will play in the Olympic qualifying tournament being held in neighbouring Argentina next February and March.
Asked if Juninho would be included, Carlos Alberto Nuzman, the president of Brazil's Olympic Committee, said: "Without doubt. Brazil will field a very strong team and will call up all their eligible players."
The competition will run for four weeks but Brazil also require Middlesbrough's pounds 4.75m signing to be available for two weeks preparation. It means he could miss about eight games when Middlesbrough may be chasing a place in Europe. Bryan Robson, the Middlesbrough manager, said: "We will tackle the problem over Juninho nearer the time."
Brazil have already claimed Juninho on Wednesday for a friendly in Argentina, which means he will miss the Coca-Cola Cup replay with Crystal Palace the same night.
Juninho lifts spirits, page 27