This year's OUE Singapore Open will be a gathering of world champions, adding more star power to an already stellar cast pencilled in for the badminton event.

The Straits Times understands that two-time world champion Carolina Marin of Spain and 2013 world champion Ratchanok Intanon of Thailand have confirmed their participation, joining their 2011 predecessor, China's Wang Yihan, in the 32-woman field.

The trio have won the last four editions of the World Championships, which are not held in Olympic years.

This will be the first time that world No. 1 Marin, who retained her world title last year, will be competing in the Singapore Open.

The left-handed Spaniard, who stamped her authority in the sport after picking up five Superseries titles last season, was scheduled to play at the Singapore Indoor Stadium last year but pulled out about a month before the event.

But, with the April 12-17 tournament acting as the last Superseries stop before the Olympics kick off in August, top players gunning for glory in Rio de Janeiro are viewing the event as crucial to their final tune-up.

Just last week, China announced a 31-strong squad for Singapore that boasted two-time Olympic and five-time world champion Lin Dan, who is widely regarded as the greatest badminton player of all time.

World No. 1 Chen Long, Olympic mixed doubles champions Zhang Nan and Zhao Yunlei and defending women's singles champion Sun Yu are also slated to compete in the US$350,000 (S$488,240) event.

And, while Ratchanok has never ventured past the quarter-finals in three previous attempts (2011, 2014, 2015), the world No. 7 knows the Singapore stop can act as both preparation and a test.

Said the 21-year-old: "The Olympics are really important to me and I don't want to miss any chances. I think it will be a challenge to see what I can do, to challenge my feelings and mentality too."

England's world No. 7 husband and wife pair of Chris Adcock and Gabrielle Adcock, newly crowned mixed doubles champions at the Badminton World Federation Superseries Finals, will also be here.

With the registration deadline still some three weeks away, more shuttlers are expected to sign up.

Also at stake are ranking points for those who need to move up the standings before the qualifying window for the Olympics closes on May 5. Only the top 34 men's and women's singles players and the top 16 pairs in each doubles event will qualify for the Games.

Said Ng Yoke Weng, the tournament's organising chairman: "We are expecting a stellar turnout of players. As each country can have up to two entries per event (at the Olympics), there will be keen competition even among players from the same country. Spectators and participants alike can look forward to competition of the highest calibre."

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