"You could have been a hell of a player," when Murray jokes with Federer

Roger Federer shared a snapshot on his Instagram account of himself practicing his serve in Shanghai.

Andy Murray, in the humorous style he's known for, took the opportunity to comment on this photo by joking: "If you'd hidden your toss better, you would have been a hell of a player."

A joke that certainly amused tennis fans. Federer and Murray have faced each other 25 times in their careers, with the Swiss leading 14-11 in their encounters.