Former world No. 4 tennis player Kei Nishikori expressed confidence Friday in his physical condition ahead of Japan’s Davis Cup World Group I tie against Colombia this weekend in Tokyo. “There’s no problem now, so I can give my best,” Nishikori, who has dealt with a series of injuries, including to his right shoulder, said at a press conference. The 34-year-old veteran, currently ranked 205th in the world, will play a match in Japan for the first time since the Tokyo Olympics in 2021 when he contests the best-of-five tie on the Ariake Colosseum hard court. “The level of my play has been pretty…