You can find a full tennis schedule for day five, along with relevant streams, here.
All of today's matches have been canceled. Most are scheduled for tomorrow, as noted by the Rio Olympics' website.
Tennis is known for its "Big Four" - the leading players in men's singles who have won a combined 46 Grand Slam titles: World No. 1 Novak Djokovic of Serbia (12), World No. 2 Andy Murray of Great Britain (3), World No. 3 Roger Federer of Switzerland (17) and World No. 5 Rafael Nadal of Spain (14).
Djokovic was knocked out in Rio's first round by London 2012 bronze medalist Juan Martin del Potro, while Federer stayed home due to injury. But a new sort of "Big Four" has emerged in the singles competitions at Rio, four players who each now have a strong shot to earn a medal: Murray and Nadal on the men's side, and World No. 2 Angelique Kerber of Germany and World No. 9 Madison Keys of the United States on the women's side.
All four will take to the courts on Wednesday, with Keys-Nadal-Murray back-to-back on Centre Court starting at 10:30 AM ET. Kerber will compete in her quarterfinal match on court 1, right after del Potro squares off with Japan's Daniel Taro.
One other name Americans should keep their eye on: Steve Johnson, who is still in the singles compeition and is guaranteed at least a medal match in doubles alongside partner Jack Sock. Johnson will compete in his third round singles match on court 3 at approximately 10 AM ET, while he'll play his semifinal doubles match on court 2 at approximately 2 PM ET (both very rough estimates).
It's been a wild ride since Rio's tennis competition started Sunday. The number one seeds have been eliminated in all possible categories so far: men's singles and doubles, women's singles and doubles.