Popular 24-year-old wrestler Endo is in doubt of making a comeback and competing in May's Summer Grand Sumo Tournament, his stablemaster said Friday.

Endo injured the anterior cruciate ligament in his left knee in March and was forced to withdraw from the Spring Grand Sumo Tournament in Osaka. Although he decided against surgery, Endo is not yet fit enough to resume sparring with before the next grand sumo tournament starts in Tokyo on May 10.

On Friday, Endo was limited to doing some light training at the Oitekaze stable. Should he fail to take part in Tokyo, Endo will certainly be demoted from the elite makuuchi division to the second-tier juryo ranks.