SAN DIEGO, Calif., June 15 (Reuters) - Fourteen years after becoming the youngest winner on Japan"s golf tour as a humble 15-year-old amateur, Ryo Ishikawa is on the verge of missing out on his dream of playing at the Olympics on home soil. Only a very high finish at this week"s U.S. Open can earn Ishikawa the second spot on the Japan team alongside Masters champion Hideki Matsuyama for the Olympic golf tournament at Kasumigaseki Golf Club. "Right now I"m just focused on my own goal, which is just trying to do my best this week against the golf course," he told Reuters on Tuesday after a practice round at Torrey Pines. "I think I would need a top three (finish) for the Olympics. That"s tough for anybody. My best finish in a major is a tie for 20th (at the 2011 Masters), so I think my goal is to have my best finish, inside top 20. "Top 15 would be fantastic for me." Matsuyama, ranked 15th in the world, is a lock for the Japan team with 78th-ranked Rikuya Hoshino occupying the second spot while Ishikawa, ranked 145th, is fifth on the list. His career has never quite taken off internationally but he remains a force on his home tour and recently won a 36-hole U.S. Open qualifying event to punch his ticket to Torrey Pines. As much as it is all about business this week, the 29-year-old took time to savour the experience. After his drive at the final hole struck one of the gums that dot Torrey Pines, he took the time to pick up a piece of bark and smell the oily aroma. Even if he fails in his bid for Tokyo, Ishikawa will not give up his dream of representing his country at the Games. "At Rio I couldn"t make it, and this time I"m standing in a tough position to make the Olympics, but in the near future I definitely want to make it as a Japanese," he said.