Japan’s former tennis world No. 4 Kei Nishikori lost on his return to the ATP tour on Thursday, going down 6-3, 6-4 against Austrian Sebastian Ofner in the first round of the Miami Open. The 34-year-old Nishikori had hip joint surgery in January 2022 before returning to the top-tier ATP Tour last July at the Atlanta Open, but a left knee injury suffered at the tournament saw him sidelined again. Nishikori, currently ranked 351st, was a wild card at Miami. The 40th-ranked Ofner did not allow a single break to advance. “I was playing with good rhythm at practice but it was different in a real ma…