Pro tennis players have been wondering aloud whether arm injuries in their sport are related to the week-to-week changing of the tennis balls used by tournaments.

Novak Djokovic made a triumphant return to Perth after a decade and led Serbia to a 2-1 win over China at the United Cup.

Three environmental activists have been arrested at Wimbledon after running onto one of the courts and disrupting two matches by throwing orange confetti and puzzle pieces onto the grass.

How much do you know about Wimbledon.

Venus Williams is set to make her 24th appearance in the singles draw at Wimbledon after the 43-year-old American was given a wild-card entry.

Top-ranked Iga Swiatek's 37-match winning streak has ended with a straight-set loss to Alize Cornet in the third round at Wimbledon.

Katie Boulter was back on the grass at Wimbledon two days after the death of her grandmother.

There will be eight American men in the third round of Wimbledon for the first time since 1995.

Nick Kyrgios has been fined $10,000 for unsportsmanlike conduct in his first-round Wimbledon victory.

An Australian Open courtesy car waits outside the Grand Hyatt hotel in central Melbourne, Australia, Thursday, Feb. 4, 2021. All competition at six Australian Open tuneup events scheduled for Thursday was called off after a worker at one of the tournaments' Melbourne quarantine hotels tested positive for COVID-19. The Australian Open is scheduled to begin Monday. Williams won her last major title at the 2017 Australian Open, when she was pregnant with her daughter, Olympia. On the bottom half of the draw, defending Australian Open champion Sofia Kenin rallied from a set and a break down to fend off Jessica Pegula 5-7, 7-5, 6-2.

Serbia's Novak Djokovic celebrates after defeating Canada's Denis Shapovalov in their ATP Cup match in Melbourne, Australia, Tuesday, Feb. 2, 2021. (AP Photo/Hamish Blair)MELBOURNE – Rafael Nadal didn't make it for Spain's ATP Cup opener because of a sore back, deciding it wasn't worth the risk a week ahead of the Australian Open. Nadal played more of a hand in that, with Djokovic limiting his time on court because of a blister. Back at Melbourne Park, where he has won a record eight Australian Open titles, he had plenty of energy to consume. Osaka, who won the U.S. Open last year and the Australian Open in 2019, will next face No.