What was that thing on Djokovic's chest at the French Open? He jokes it's connected to Iron Man

Novak Djokovic prepares to serve against Márton Fucsovics in the French Open second round. (Tim Clayton/Corbis/Getty Images)

PARIS -

So, what exactly was that metal-looking object about the size of a bottle cap that was taped to Novak Djokovic's chest at the French Open?

He was asked about it. He didn't give a straight answer.

During the changeover between the end of the first set and the start of the second during the 22-time Grand Slam champion's 7-6 (2), 6-0, 6-3 victory over Marton Fucsovics at Roland Garros on Wednesday night, Djokovic removed his reddish polo shirt and swapped it for another.

Nothing out of the ordinary there, especially after a set that lasted 1 1/2 hours.

Here's what was unusual: TV cameras in Court Philippe Chatrier zoomed in on some item that was placed right in the middle of Djokovic's chest. Commentators on Tennis Channel's broadcast joked about it having something to do with the Marvel Comics character Iron Man, portrayed on the big screen by Robert Downey Jr.

Maybe someone told Djokovic about that observation.

Because that was the faux explanation the 36-year-old father of two offered when a reporter wanted him to explain precisely what that thing really was.

"When I was a kid I liked Iron Man a lot, so I try to impersonate Iron Man," Djokovic said with a smile.

And then he went a step further.

"My team delivers an incredibly efficient nanotechnology to help me deliver my best on the court, so that's the biggest secret of my career," Djokovic said sarcastically. "If it wasn't for that, I probably wouldn't be sitting here."

Hmmmm.

Perhaps a sequel to this saga will come on Friday. That's when Djokovic will continue his pursuit of a third title at the French Open -- and what would be a men's-record 23rd major championship overall, breaking a tie with rival Rafael Nadal -- when he faces No. 29 seed Alejandro Davidovich Fokina of Spain.