Even with the doors on his international return slammed shut, China's disgraced swimmer Sun Yang has refused to be written off in the pool, as he shapes up for his third domestic meet since returning from a doping ban.

As China's domestic trial for major international meets, the national swimming championships have witnessed many of Sun's career highlights, paving his way to three gold medals at two Olympics — London 2012 and Rio 2016 — while seeing his popularity soar to celebrity status.

At the 2025 edition, however, fans will likely see a different side to the once flamboyant champion — a humble, discreet veteran, trying to shake off the shadow of infamy caused by his controversial anti-doping rule violation and looking to prove that he remains a force to be reckoned with.

A distance freestyle specialist in his prime, Sun has signed up to compete in four free events — the 100,200, 400 and 800 meters — in a hectic schedule at the weeklong meet, which will kick off on Saturday in Shenzhen, Guangdong province.

Although far from his best, Sun's head-to-head race with the red-hot 100m free world record-holder Pan Zhanle, who's emerged as the new poster boy for Chinese swimming in Sun's absence, in the 100m, 200m and 400m events has ignited a fair bit of interest from fans.

The championships will also provide a stern test for China's current best, including Pan, men's three-time breaststroke world champion Qin Haiyang and women's butterfly star Zhang Yufei, ahead of the 2025 world championships in Singapore this summer.

For Sun, however, his performance in Shenzhen will have little impact on the roster selection for the worlds.

In a document released last month, the Chinese Swimming Association set out clearly its rule that any athlete that has served a doping suspension of more than one year is ineligible for a national team call-up to any major international meet.

Having reiterated his innocence at multiple hearings and trials, Sun received a ban that ran from February 2020 to May 2024, imposed by the Court of Arbitration for Sport, for his violation of doping-control rules that occurred during an out-of-competition test at his residence in Hangzhou, Zhejiang province, in September 2018.

The most decorated, and perhaps most controversial, men's swimmer in China shied away from spotlight during the suspension, married a former rhythmic gymnast, and kept working out on his own, obeying the rules that barred him from doing so at any government-funded training facilities and with help from any member of national or provincial team staff.

And, in his absence, Chinese swimming moved on, with the younger generation making huge waves on the international stage.

Zhang's two golds at Tokyo 2020(women's 200m fly and 4x200m free relay) helped Chinese swimming maintain its momentum at the Games, with Qin's unprecedented clean sweep of all three breaststroke titles (50, 100 and 200) at the 2023 worlds giving it another push.

Pan then took up the baton on his Olympic debut in Paris by smashing the 100m free world record with a staggering 46.40-second sprint, later touted by pundits and analysts alike as one of the greatest moments at the Games.

Finding it too tough to find his best form at 33 years old, Sun said he took pride from these young world-beaters, believing that the future of the sport in China is in good hands.

"I think, for me, the target now is no longer about winning medals at the highest international level, although I am not quitting competitive swimming," Sun told Global People magazine earlier this year.

"My goal is trying to extend the remainder of my career at the elite level for as long as possible.

"Most of the freestylers at my age would've opted to race only in the sprint events, but I want to break the barrier for senior athletes to also be competitive in the distance events," said Sun, who held the 1,500m free world record for 12 years, until American swimmer Bobby Finke surpassed him in Paris last year with gold medal-winning time of 14:30.67.

Sun will kick off his Shenzhen meet on Day 1 with the heats and, possibly, final of the 400m, his strength event, in which he won his first Olympic gold in London, with Pan, a typical sprinter, also signing up to the middle-distance event.

In his most recent official race, at the Chinese spring championships in March, Sun clocked an impressive time of 3:47.94 over 400m, going 0.21 seconds faster than the entry "A" standard for the Singapore worlds.

Pan will also race the 50m free to test his pace in the ultra sprint, while other notable entries in the men's events include Qin in all three breaststroke disciplines, three-time world champion Xu Jiayu in all three backstroke events, and Tokyo 2020 gold medalist Wang Shun in both individual medley events (200m and 400m).

On the women's side, Zhang is expected to reign supreme in both 50m and 100m butterfly, where she will be challenged by IM specialist Yu Yiting, who's determined to make her breakthrough in the single-stroke event.

With six more 50m events in backstroke, breaststroke and butterfly now added to the program at the Los Angeles 2028 Olympics, the national meet has also seen a spike in entries to those events, particularly among women.

Yu, who's set to swim in seven events in Shenzhen, including the 50m fly and back, said that the addition of more sprint events has spurred on the entire field to push harder.

"I think it's quite an incentive, one that will spark an extra push from everyone. I will try my best to see how much faster I can go," said the 19-year-old all-rounder, who helped China's women clinch two relay bronze medals in 4x100m free and medley in Paris.

sunxiaochen@chinadaily.com.cn