Nadal's luxurious thatching has long been a feature of the Spaniard's trademark look, which has seen him voted as one of the world's sexiest sportsmen on numerous occasions.
However, the hair on the 27-year-old's head is now starting to thin, exposing parts of his scalp to daylight for the first time in his adult life.
Murray, who is good friends with Nadal, recognises that he has his own follicle issues, with a hairline that is steadily receding.
who loses their hair first out of me and rafa?— Andy Murray (@andy_murray) November 8, 2013
Murray's tweet came just days after he revealed that Nadal once pranked him in a New York restaurant by texting him pretending to be a secret admirer.