Tendulkar, who will turn 48 next month, retired from the professional game in 2013 after notching a still unmatched 100 international centuries in a prolific 24-year career.
He returned to the crease recently as captain of the India Legends team in a promotional event called the Road Safety World Series in Raipur, in the state of Chhattisgarh.
"I have been testing myself and taking all the recommended precautions to ensure Covid is kept at bay. However, I have tested positive today following mild symptoms," Tendulkar said on his Twitter handle.