Defending world and Olympic men's figure skating champion Yuzuru Hanyu has yet to return to the ice after suffering an injury that forced him out of last month's NHK Trophy, Japan Skating Federation director Yoshiko Kobayashi revealed Sunday.

According to Kobayashi, Hanyu is still feeling the effects of a right knee injury sustained during practice on Nov. 9, casting doubts over his participation at the upcoming national championships.

Kobayashi said Hanyu told her his condition has improved, but that he has not trained on the ice at his base in Toronto because he is still experiencing soreness in the knee.

He said he is undergoing treatment and rehabilitation.

Although the Dec. 21-24 national championships in Tokyo serve as a qualifier for February's Pyeongchang Olympics, Hanyu is virtually guaranteed to represent Japan at the games, having met the selection criteria through his No. 1 world ranking and other results.

Asked about Hanyu appearing at the nationals, Kobayashi said, "It is an important selection competition, and the Olympics are a big goal, so with that in mind we would like to think things through together."

Hanyu fell while attempting a quad lutz during official practice for the NHK Trophy, the fourth event of the Grand Prix Series, injuring the lateral collateral ligament in his right knee and also hurting his right ankle.

He said on Nov. 12 that he would need 10 days of complete rest in order to regain fitness in time for the nationals.

"I have been told by the doctor that I need 10 days of complete rest," Hanyu said through the JSF. "Following that, it will take three to four weeks to return and get back to where I was (physically)."