Japan on Tuesday marked 500 days to go until the opening of Rugby World Cup 2019, as scandals continue to plague the preparations for the tournament.

Twenty teams will compete across 12 venues in Japan when the competition kicks off on Sept. 20, 2019. However, the identity of Japan's opponents in the opening game at Ajinomoto Stadium (Tokyo Stadium) hinges on an investigation into player eligibility that could see Russia replace Romania as the top European qualifier.

The European qualifying saga has already seen five Spanish players handed long bans for physically and verbally abusing the Romanian referee after their defeat to Belgium handed the Oaks a spot in Pool A. Adding to the confusion, reports from Europe suggest Spain and Belgium could also be prevented from advancing to the next stage of the convoluted qualifying process for fielding ineligible players.

This follows the expulsion of Tahiti, with the Cook Islands now set to play the winner of the Asian qualifying tournament -- featuring Hong Kong, Malaysia and South Korea -- for a place in the four-team repechage.

(Tokyo's Ajinomoto Stadium)

Within Japan, the tournament, already overshadowed by the Tokyo Olympics the following year, has seen the venue for the Nov. 2 final moved to Yokohama -- not even on the original shortlist of host cities -- after Prime Minister Shinzo Abe ordered the redrawing of plans for the new National Stadium due to soaring costs.

Additionally, the naming of training venues was delayed by eight months after many of the locations on the original list drawn up by the local organizing committee did not meet the required standard.

World Rugby Chairman Bill Beaumont, however, remained positive, saying Tuesday, "With 500 days to go preparations for Rugby World Cup 2019 are on track and moving forwards at a fast pace."

Organizers have started selling tickets and launched the recruitment process for some 10,000 volunteers for Asia's first Rugby World Cup. Volunteer applications run through July 18.

Construction or refurbishment of the 12 venues that will host a total of 48 matches is also well under way.

The only new venue for the tournament is being built in northeastern Japan's Kamaishi city and set for completion on Aug. 19. The Kamaishi Recovery Memorial Stadium in the Iwate Prefecture city, which suffered major damage in the March 2011 earthquake and tsunami disaster, will host two matches.

(Michael Leitch [top] and Japan will kick off their World Cup campaign in 500 days)

Japan's older, traditional rugby venues that are going through refurbishment are also set to host matches in October.

Kumagaya Rugby Ground in Saitama will host Top League matches, while the national team will play at Osaka's Hanazono Rugby Stadium on Oct. 26.

Meanwhile, the Brave Blossoms are aiming to improve on their performance at the previous tournament in 2015, when they defeated South Africa in one of the biggest upsets in the history of the sport.

They will face Italy and Georgia in international friendlies in June at three venues used at the World Cup.

"If we spend the remaining 500 days well, our chances of winning (at the World Cup) will improve," scrumhalf Fumiaki Tanaka, a member of the 2015 team, said Monday. "Winning (the June friendlies) will enable us to go into the World Cup with confidence."

(The Webb Ellis Cup)