(Photo by Dylan Buell/Getty Images) Getty ImagesDefending champion Carlos Alcaraz has withdrawn from the Cincinnati Open, throwing into doubt his fitness for the upcoming U.S. Open beginning later this month. “Carlos Alcaraz has withdrawn from the Cincinnati Open. 3 and French Open champion Alexander Zverev also in the field. “We hope Carlos is coming back as well… because tennis needs him," Sinner said after winning Wimbledon last month. MORE FOR YOUAlcaraz beat Sinner in last year’s Cincinnati Open final and then beat the Italian in four sets in the U.S. Open final the following month.