Arsenal's young Mexican striker Carlos Vela has travelled to Manchester ahead of Wednesday's Champions League game after spending a day in quarantine due to fears over the swine flu outbreak.
Vela, 20, was told to stay away from training on Monday 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 to keep him at home and not get him to the training ground."
He added: "Now he has the all-clear and today (Tuesday) 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."
Defender Kieran Gibbs, however, is a major doubt. Gibbs is struggling with an ankle injury, while his likely replacement Mikael Silvestre is not certain to be involved either as he tries to shake off a back complaint.
Captain Cesc Fabregas (ankle/knee) and defender Johan Djourou (knee) also got through training but leading scorer Robin van Persie (groin) and left-back Gael Clichy (back) remain sidelined.
Russian midfielder Andrey Arshavin is ineligible and centre-half William Gallas (knee) and long-term absentee Tomas Rosicky will miss the rest of the campaign.
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