Manchester United midfielder Darren Fletcher admits he remains in the dark over the mystery virus he was hit with last season.
Fletcher made his comeback this week at Benfica.
"It has all been resolved now but I never got to the bottom of it," he admitted. "I felt drained and weak and was bed-bound for a bit.
"But the biggest thing was losing the weight.
"The virus was bad but for someone like me to lose the weight I did, it was really difficult to put back on. It took me a good few months to get back to my natural weight. "Eventually I got there though and I feel stronger for it now.
"I have even put on a little bit more, which will be beneficial for me as well."
