But the initial reports were positive, according to Twins assistant general manager Rob Antony, who heard from head trainer Dave Preumer.
"Pruemer talked to the doc yesterday, who said he'd call today if there was anything to the last tests, but he said he was encouraged," Antony said. "He's through most of [the symptoms]. Hopefully it won't be too long."
Antony added the Fuld is expected to do some workouts once he returns to the Twin Cities, but he still wasn't cleared for baseball activities.
"Fuld is flying back today and is going to work out today," Antony said. "But he still needs three good days [before baseball activity]. The biggest thing was getting some peace of mind. There was nothing major or anything like that. It's a situation where he doesn't have to be too concerned."
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. Alex Smith is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.