Djokovic has not played a match that counted since the semifinal loss to Sinner in the French Open. He showed fight against the world's top-ranked player, but ran out of gas during his fourth-straight loss to the 23-year-old phenom.

Novak Djokovic says he would like to keep playing tennis for several more years. But he also acknowledges it's impossible to know for sure whether he will even be back at Wimbledon again.

As Novak Djokovic prepares for his 20th Wimbledon appearance, former American tennis pros share their insights on whether the 24-time Grand Slam champion can add another title to his legendary career.