Devastated Rafael Nadal vowed the knee injury that forced him out of the US Open semi-finals on Friday won't stop him chasing more Grand Slam glory. The Spaniard said the trouble was the familiar tendinitis he's dealt with for a decade — unpredictable but not career-threatening. "I know what I have," he said after limping off having lost two sets to third-seeded Argentine Juan Martin del Potro. "I know what is going on with the knee. I know how I have to work to be better as soon as possible."

But it was galling for the player famed for his fighting spirit to hobble out of a second Grand Slam of 2018, having retired in the fifth set of his Australian Open quarter-final against Marin Cilic with a torn inner hip muscle. "It's not about losing, it's about not having the chance to fight for it," he said. "I'm having two great years," added Nadal, who was trying to complete a French Open-US Open double for the second straight season.