Rafael Nadal admits he does not know whether he will be fit to face Nick Kyrgios in Friday’s Wimbledon semi-finals after an abdominal injury nearly forced him to quit against Taylor Fritz.

The second seed had to take a medical time-out in the second set but battled through to win 3-6, 7-5, 3-6, 7-5, 7-6 (10/4) in a gruelling contest lasting four hours and 21 minutes.

Earlier, Australian maverick Kyrgios cruised past Chile’s Cristian Garin with relative ease 6-4, 6-3, 7-6 (7/5).

Nadal, the 2008 and 2010 champion, said in his post-match press conference that he was unsure over his ongoing participation in the tournament as he targets the third leg of a rare calendar Grand Slam.

“I can’t give you a clear answer because if I gave you a clear answer and tomorrow another thing happens, I will be a liar,” said the 36-year-old.

Nadal, who was given pain relief during the match, said he would have tests before deciding whether to play on at the All England Club.

The Spaniard admitted his father and sister had been gesticulating for him to quit his quarter-final match against Fritz but said he “hated” the idea.

“I fought,” he said. “Proud about the fighting spirit and the way that I managed to be competitive under those conditions.”

Kyrgios, ranked 40th in the world, is a major threat, even to a fully fit Nadal.

The 22-time Grand Slam champion leads 6-3 in their head-to-head meetings but Kyrgios beat the Spaniard on his way to the quarter-finals in 2014 before Nadal gained revenge three years ago.