For Novak Djokovic, winning Wimbledon for an eighth time would be his record-extending 25th major. At age 38, the Serbian knows his singles tennis days are numbered. Djokovic touched on retirement earlier this month with the Grand Slam on grass looming and was asked again about the possibility of stepping away prior to his opening-round match in London next week.

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.