During his short offseason, Koepka had stem cell treatment on his left knee because the patella tendon was partially torn. As Li Haotong of China was making his debut at the Presidents Cup, Guan Tianlang was preparing to qualify for the PGA Tour Series-China. Ishikawa showed signs of getting back to form last year when he won three times on the Japan Golf Tour, his first titles since 2016 and his biggest year in Japan since 2010. Otherwise, the Japan Golf Tour season doesn't start until a week after the Masters. The last seven rounds on the PGA Tour in Hawaii were played under lift, clean and place rules.