Bastian Schweinsteiger has revealed that his recent knee trouble was caused by a tick.
The Bayern Munich midfielder has been sidelined recently with a mysterious infection that had given him pain in his right knee.
And he has now declared that he was suffering from Lyme's disease, a bacterial infection which can produce symptoms such as muscle and joint pains, as well as arthritis, cognitive defects, neurological complaints or fatigue.
Ticks can transmit diseases to humans and Schweinsteiger believes he was bitten by one of the blood-sucking mites.
"It turned out to be a tick bite which stopped me from being able to train," explained the German.
"The doctors diagnosed me with having Lyme's disease."
Schweinsteiger has been treated with antibiotics and returned to training, although it is unclear whether he will play any further part for Bayern this season.
His last game was the 2-1 victory over Hannover three weeks ago.