MUMBAI, Sept 17 (Reuters) - Asia"s loss is San Diego"s gain after the Southern Californian city bagged a one-year licence to host an ATP 250 event this month and audition for a permanent spot on the calendar. With events in China and Japan wiped off the schedule due to the COVID-19 pandemic, the men"s tour was in the market with one-year licences for new tournaments to fill the void caused by the cancellation of the Asian swing of events. "We had a group in San Diego that had been wanting to bring an event here for a while," Daniel Vallverdu, managing director of the San Diego Open, which runs from Sept. 27-Oct. 3, told Reuters. "But it"s definitely been a challenge ... we had just six and a half weeks from the time it got approved. We had no structure in place and had to start from scratch." The spot in the calendar a week before the Masters 1000 event in Indian Wells - a two hour 30 minute drive from San Diego - has helped the ATP 250 event attract a strong field. Russia"s world number five Andrey Rublev and Norway"s 10th ranked Casper Ruud will be joined by a host of other top 20 players plus Japan"s Kei Nishikori and Britain"s Andy Murray at the $600,000 hard court event on the Pacific Ocean coast. Despite small tournaments feeling the pinch in the last 18 months due to the pandemic"s impact on the global economy, Vallverdu said it made sound business sense for the organisers. Along the lines of the U.S. Open, the tournament will allow a capacity crowd but spectators must show proof of vaccination. "It"s a long term investment," said the 35-year-old Vallverdu, who has coached major champions like Murray, Stan Wawrinka and Juan Martin del Potro over the last decade. "With a single year licence our goal is to deliver a world class event and showcase what an amazing city San Diego is. Southern California is the perfect place for tennis and we hope to have a tournament here permanently. "It felt like the city wanted an event like this for a while. We had very positive reaction from the private sector, local sponsors and tennis fans."