Roger Federer and Naomi Osaka have each withdrawn from the Italian Open with injuries.
Federer, who had been set to take on Stefanos Tsitsipas in the quarterfinals, bowed out with an injury to his right leg.
On Thursday, Federer played through two matches, beating Joao Sousa in straight sets and dispatching Borna Coric in three.
"I am disappointed that I will not be able to compete today," Federer said. "I am not 100 percent physically and, after consultation with my team, it was determined that I not play. Rome has always been one of my favorite cities to visit and I hope to be back next year.