London, England (CNN) -- British boxing champion Amir Khan was briefly hospitalized in England after returning from watching the World Cup in South Africa, his manager said Tuesday.
The WBA world light welterweight champion "had been feeling weak" and went in for tests on Sunday, said his manager, Asif Vali.
All the tests came back negative, Vali said, without specifying what they were.
"He is currently at home resting and taking plenty of fluids and suspects he may be suffering from exhaustion due to an intense travel schedule over the past three days," Vali said.
Khan, 23, from Bolton, England, won a silver medal at the 2004 Olympics.
CNN's Lianne Turner contributed to this report.