Novak Djokovic dominated men’s tennis this year, but with Roger Federer and Rafael Nadal wearing down physically, 2021 also signaled a changing of the guard: Stefanos Tsitsipas reached the French Open final; Matteo Berrettini reached the Wimbledon final; Alexander Zverev won the Olympic gold medal; and Daniil Medvedev reached the Australian Open final and then won the United States Open. All are 25 or younger.
Now a new crop of youngsters, 24 and under, is charging up the rankings, but some will stall.
To separate themselves from their peers, each must refine his game; these 10 are most likely to join the sport’s elite, if they improve one aspect of their game.