Renowned tennis coach Patrick Mouratoglou says Stefanos Tsitsipas could pose a real threat to Rafael Nadal and Novak Djokovic at the French Open as the Greek sent a warning to rivals with his Monte Carlo victory. Last year, Tsitsipas won his maiden Masters title in Monte Carlo before finishing runner-up at the French Open. This year, Tsitsipas kicked off his clay season by winning back-to-back Monte Carlo titles and it is not a secret that he will be eyeing his maiden Grand Slam title at Roland Garros. “With his huge season in 2021 on this surface, Stefanos had a lot …