TOKYO — Defending champion Nathan Chen heads to the world figure skating championships in Japan balancing the rigors of competition with the scholastic requirements of being an undergraduate at Yale.

Coming off a long break from the US Nationals in January where he captured his third straight national title, Chen said the plan is pretty much to stick with that program at the worlds where his main rival is expected to be Olympic champion Yuzuru Hanyu, who has been recovering from an ankle injury.

"It's going to be basically identical to nationals," Chen said of his program in a conference call. "I haven't really trained anything else, so unless something super surprising happens the week of (worlds) it'll be basically that."

During the nationals, Chen landed four quad jumps in his free skate routine, one of which was in combination.

At the Olympics last year, Chen became the first man to land six quadruple jumps in program — that wasn't enough for a medal, but he did win the free skate. He later won the world title, and now he seems as strong as ever despite balancing training with his studies at Yale.

Despite the hectic schedule, the 19-year-old Chen says he has no regrets balancing the two.

"It was just an experience I didn't want to give up on before I even tried it," Chen said. "I'm really glad I gave myself a shot to attempt both. I've really, really enjoyed myself in college, and skating has been going well too, so I can't really complain."

As for Hanyu, the Pyeongchang Olympic champion has been flying under the radar. Whether training at his base in Toronto or in his hometown of Sendai, nobody in Japan has seen much of the elusive skater.

Hanyu's coach Brian Orser has said he is "very confident" the two-time Olympic gold medalist will be able to compete at the worlds which get underway this week at Saitama Arena, north of Tokyo.

Hanyu is recovering from a right ankle injury that forced him to skip the Dec 21-24 Japan nationals.

After twisting his right ankle in a fall in practice at the Rostelecom Cup on Nov 17, Hanyu was told he needed three weeks of rest and one month of rehabilitation to recover from a ligament injury sustained in the fall.

He claimed his second straight Grand Prix series title of the season despite the injury, but was later forced to withdraw from the Grand Prix Final for the second straight year.

Despite the low profile, nobody is counting out Hanyu.

Hanyu suffered a similar injury at the 2017 NHK Trophy before making a comeback at Pyeongchang, where he became the first male figure skater to win consecutive Olympic golds since American Dick Button in 1948 and 1952.

With Hanyu absent, Chen's title at last year's worlds in Milan, Italy, was the first for an American man since Evan Lysacek won gold in 2009.

Olympic silver medalist Shoma Uno, the 2018 world silver medalist, will also be a medal contender on home ice.

Uno heads into the worlds on a high having won the Four Continents last month. In that competition, Uno showed his resolve when he finished fourth in the short program and then won the free skate to claim the overall title. It marked the first time he won a major international competition.

Uno also had an impressive 2018, winning Skate Canada, the NHK Trophy and the Japan nationals.

Russia's Alina Zagitova will highlight the women's event. The 2018 Olympic champion is a huge hit in Japan but has been challenged recently by rising Japanese skaters Rika Kihira and Kaori Sakamoto.

Both Kihira and Zagitova are just 16 years old but it was Kihira who upstaged the Russian skater at last year's Grand Prix finals in Vancouver.

Also likely to be in contention is two-time world champion Evgenia Medvedeva of Russia.

The Olympic silver medalist has struggled in her first season since moving to Canada to train, finishing third and fourth at two Grand Prix events and seventh at the Russian nationals in December. But Medvedeva recovered to win a Russian event last month widely considered to be an unofficial qualifier for the worlds.

AP