CHICAGO - United States forward Landon Donovan has been quarantined suffering from swine flu and his team mates are to be treated as a precaution, the U.S. Soccer Federation said on Friday. The federation said in a statement that Donovan had "most likely contracted the (H1N1) virus while with his club team the L.A. Galaxy" before the U.S. team's trip to Mexico City for Wednesday's 2-1 World Cup qualifying loss to Mexico. "As a precaution all members of the U.S. team delegation who came in close contact with Donovan have been advised to take a course of Tamiflu," it said. The players do not need to be quarantined if they do not have any symptoms of the virus, the federation added citing guidelines from the Centers for Disease Control in the United States. Donovan was tested on Thursday, the morning after returning from Mexico City, and David Wallis, a doctor with the U.S team medical staff, said he had only mild symptoms and should be fine in a few days.