Wincing from abdominal pain, unable to play his customary relentless style of tennis, Rafael Nadal worried that he might need to stop playing in the Wimbledon quarterfinals against Taylor Fritz. With much of the crowd roaring and standing after Nadal’s best strokes, he twice erased one-set deficits against 11th-seeded Fritz and emerged with a 3-6, 7-5, 3-6, 7-5, 7-6 (10-4) victory Wednesday to reach his eighth semifinal at the All England Club. “For a lot of moments,” Nadal said, “I was thinking, ‘Maybe I will not be able to finish the match.'” On Friday, Nadal is scheduled to play Nick Kyrgios, a 27-year-old Australian who will be making his Grand Slam semifinal debut after a 6-4, 6-3, 7-6 (5) victory over Cristian Garin of Chile. But will he? After being given anti-inflammatories during Wednesday’s match to “relax” the muscle, he said he wasn’t sure of his availability for Friday’s semifinal vs. Kyrgios.