Ma Long competes during the table tennis team's preliminary match at the Chinese National Games in Tianjin, June 28, 2017. [Photo/Xinhua]?

TIANJIN－Olympic table tennis champion Ma Long is facing arguably the toughest challenge of his career as his creaking body puts added strain on his title defense at the Chinese National Games in Tianjin this week.

The world No 1 is at the technical and mental peak of his powers after claiming Olympic gold in Rio last year. But the same can't be said for his physical condition.

Ma's coach, Zhang Lei, confirmed last week that injuries are troubling the two-time singles world champion, who's representing Beijing at the Games. And with three events (singles, doubles and team) to contend with, the 28-year-old's body will be pushed to the max.

"The old injuries to his hip joint and wrist are getting worse," said Zhang.

"They resurfaced in his training last week and he had to take cortisone injections and take some time off of training for recovery.

"If he goes deep in each event, he will have to play two or three matches each day and face stiff challenges physically."

Ma is reluctant to dwell on his injuries, saying on Sunday: "On the whole, I'm feeling alright and not quite worried about my injury troubles, but I have to say it's quite tough to play in the National Games and you have to play your best in every match in order to avoid early elimination."

Ma will consistently be up against more capable opponents in Tianjin than he faced in Rio, since most of the world's top-ranked players are from China but only the country's top two compete in the Olympics.

His chief rival for glory is 20-year-old world No 2 Fan Zhendong. Ma emerged victorious after an epic seven-set thriller between the two at this year's world championships in Germany, and also beat the youngster for gold at the last National Games, in 2013.

But Fan's coach in the PLA delegation, two-time Olympic runner-up and coach of the Chinese national team Wang Hao, reckons Fan is on the brink of a breakthrough.

"Ma is a master in skill and experience, so he was able to beat Fan in the world championship final in a seven-set showdown, but that defeat is helping Fan to build up his own experience in handling big events and key moments," said Wang.

"That's just what Fan needs the most in order to start his era of dominance in the sport."

Xu Xin and Zhang Jike, the London 2012 gold medallist who Ma dethroned in the Rio Olympics final, are another two of the world's top five with designs on gold in Tianjin.

"Chinese players know each other so well, both in terms of skill and temperament, so it makes the job easier to find a way to defeat the star players," said Wang.

Veteran coach Zhou Shusen, who is with the Shandong delegation, concurs.

"You don't need to play so many Chinese players on the way to win in the Olympics, as only two players from each country are allowed to compete at the Olympics," said the 76-year-old.

"But here you have to play a couple of Chinese on the way to the crown.

"Each of your opponents is one out of hundreds or thousands, and no one is an easy target."