Former World No. 1 Lleyton Hewitt will captain Team Australia at the 2021 ATP Cup.

A view of the city of Belgrade, which will host an ATP Tour event for the first time since 2012.

A view of the Singapore skyline, with the financial district in the distance.

Frances Tiafoe reached the US Open fourth round for the first time in 2020.

Frances Tiafoe will next compete at the Great Ocean Road Open in Melbourne.

Matteo Berrettini will attempt to qualify for the Nitto ATP Finals for the second time in three years.

Felix Auger-Aliassime will donate $5 to EduChange for every point he wins during the 2021 ATP Tour season.

Poland's Hubert Hurkacz moves up six places to No. 29 in the FedEx ATP Rankings.

Lorenzo Musetti makes his 2021 ATP Challenger Tour debut in Istanbul.

Mike Bryan and Bob Bryan retired last August following their illustrious careers, which lasted more than two decades.

Jannik Sinner, a 19-year-old Italian, is the youngest player in the Top 100 of the FedEx ATP Rankings.

Stockholm Open, an ATP 250 tournament.

Millennium Estoril Open, an ATP 250 tournament.

New York Open, an ATP 250 tournament.

Daniil Medvedev won the biggest title of his career at the 2020 Nitto ATP Finals.