Manchester United may be without new defender Gabriel Heinze for the start of the season because the Argentine could be playing in the Olympics.
Heinze's absence would leave United short at the back
Heinze, 25, has been named in his country's provisional squad for Athens.
And should he be selected for the final 18, he would miss the Community Shield, the first four Premiership games and the Champions League qualifier.
That would give United a defensive crisis with Rio Ferdinand banned until September and John O'Shea injured.
O'Shea has already been ruled out of the club's tour of the United States, which begins next week.
Heinze, who signed from Paris St Germain for £6.9m last month, is currently playing for Argentina in the Copa America.
It was expected he would be overlooked for the Olympics as the rules state only three players in each side can be over 23-years-old.
Now United boss Sir Alex Ferguson faces a nervous wait to see if Argentina boss Marcelo Bielsa chooses Heinze as one of his over-age contingent.
United have already lost Portuguese winger Cristiano Ronaldo to the Olympics and the absence of Heinze would be a major blow.