Stefanos Tsitsipas has parted ways with Goran Ivanisevic after a "brief but intense" coaching spell.
Greece's Tsitsipas began working with Ivanisevic in May after winning only two matches in his past four Grand Slam appearances.
However, he won only one match during the grass-court season and was two sets down against qualifier Valentin Royer in the Wimbledon first round before retiring injured.
Croatian Ivanisevic - a former Wimbledon champion who worked with Novak Djokovic for six years - was also critical of Tsitsipas' fitness.
"I'm thankful for the time, effort and energy Goran dedicated to me and my team," Tsitsipas, 26, wrote on Instagram.