Badminton superstar Kento Momota has been denied a spot on Japan's team for this summer's Rio de Janeiro Olympics after receiving an indefinite suspension from the Nippon Badminton Association on Sunday.

The 21-year-old Momota, the second ranked player in the world, and Kenichi Tago, 26, have admitted to gambling at casinos in Japan, which are illegal. Momota had already passed the necessary qualifications to represent Japan in Rio, but will not be nominated by the badminton association.

Tago, who competed at the 2012 London Games and became the first six-time national champion in 2013, was deregistered indefinitely by the association in a heavier punishment.

According to details provided by their club team, NTT East Corp., Momota, at Tago's invitation, gambled at casinos about six times from October 2014 to January 2015 and lost roughly ¥500,000 (about $4,600). Tago was a frequent gambler, losing about ¥10 million in about 60 trips to gambling establishments from October 2014 to January this year.

"I went to a casino for the first time in a country where it's legal, and the thrill of it gradually took over my senses," Momota said during Friday's press conference.

On March 25, Momota threw out the ceremonial first pitch at Tokyo Dome as NPB's Yomiuri Giants kicked off their 2016 season.

"I'll aim to win (in Rio) so that I can build toward 2020 (and the Tokyo Olympics)," Momota said after he was honored.

In November, a NPB investigative committee reported that three Giants' pitchers, who received indefinite bans for their involvement in betting on baseball games, had visited casinos. The report labeled casinos as a "hotbed" leading to betting on baseball games.