Arsenal's young Mexican striker Carlos Vela is with the squad for their Champions League game at Manchester United after spending a day in quarantine due to fears over the swine flu outbreak.
Vela, 20, was told to stay away from training yesterday after a visit by some Mexican friends last week.
Mexico is the centre of the outbreak of the disease and Arsenal manager Arsene Wenger said: "It looked to be a massive problem because we were asked yesterday to keep him at home and not get him to the training ground.
"Now he has the all-clear and today he was free again to attend training."
Wenger added: "It was basically down to the fact he had visitors from Mexico, friends who came to visit him last week."