Novak Djokovic plays at Wimbledon with the number ''23'' printed on his white tennis shoes

Novak Djokovic's white tennis shoes with the green “23” printed on the heel might have to be replaced soon.

The seven-time Wimbledon champion has won 23 Grand Slam singles titles, and he could add to that total on Sunday, July 16, if he wins three more matches at the All England Club.

“Well, obviously if it happens in less than a week's time that I reach the 24, then we'll have to use the 24, I guess,” Djokovic said. “It's not going to be a big problem to do that.” Djokovic reached the Wimbledon quarterfinals for the 14th time on Monday, July 10, beating Hubert Hurkacz 7-6 (6), 7-6 (6), 5-7, 6-4 in a match that started Sunday, July 9, on Centre Court. He will next face Andrey Rublev for a spot in the semifinals.

Djokovic won his men's record 23rd major title last month at the French Open, only a few months after winning the Australian Open.

A detail on Djokovic’s shoes showing ‘23’ in reference to the number of Grand Slam singles titles he has won. (Source: AP)

“I think it's cool,” he said. “It's nice to mark the achievement, historic achievement, in this way.” Djokovic has surpassed both Roger Federer and Rafael Nadal and is even with Serena Williams with 23 major titles. If he wins the title on Sunday, he would equal the overall record of Margaret Court.

“I'm very proud of the achievement, obviously,” Djokovic said, “but I'm already with my thoughts on this tournament and trying to make the most out of it.”