Summer Olympics 2016: Things to Watch for on Day 2 in Rio

If Day 2 is anything like the first day of the Rio Olympic Games, we're in for a treat Sunday.

Action is scheduled in 22 different sports, eight of which will feature medal events: archery, cycling, diving, fencing, judo, shooting, swimming and weightlifting. The featured attraction among medal competitions again will be in swimming, where four finals are part of the action at the Olympic Aquatics Stadium.

Also on Sunday: women's gymnastics gets underway with qualifying rotations, the U.S. women's basketball team begins pursuit of a sixth straight Olympic gold when it opens group play against Senegal and men's soccer action resumes with the second set of group-stage matches.

Here's a look at what to follow on Day 2:

Breaking Through for Gold?

Michael Sohn/Associated Press/Associated Press

The U.S. grabbed three silver medals in the pool Saturday, but Sunday's swimmers have a great chance to give the country some gold, starting with 19-year-old phenom Katie Ledecky.

Ledecky begins pursuit of what she hopes will be a sweep of three individual events when she competes in the 400-meter freestyle, an event she holds the world record in. After swimming the final leg of Team USA's silver-medal 4x100 relay team on Saturday, Ledecky enters the 400 free with the two fastest times ever in the event, while teammate Leah Smith has the second-fastest result this year.

The 21-year-old Smith is making her Olympic debut, while Ledecky, 19, burst onto the scene during the 2012 Games in London.

The women's 100-meter butterfly features a lone American, but it's the defending Olympic champion. Dana Vollmer qualified in her semifinal heat on Saturday in 57.06 seconds, 0.01 seconds behind Japan's Rikako Ikee but way behind Sweden's Sarah Sjostrom. The world-record holder broke Vollmer's Olympic mark from 2012 by finishing in 55.84 seconds.

The 22-year-old Sjostrom took fourth in London.

On the men's side, 35-year-old Anthony Ervin looks for his first Olympic medal since winning a pair in 2000 in Sydney, including a silver as part of the 4x100 men's freestyle relay team. He's part of the U.S. squad that's seeded 13th out of 16 countries heading into the semifinals but will get the added boost of 18-time gold medalist Michael Phelps being part of the group.

It's the first of what could be 12 races (depending on qualification) over seven consecutive days for the 31-year-old Phelps.

And individually, Kevin Cordes and Cody Miller are in the field for the men's 100-meter breaststroke title. However, it will take a major effort to beat out Great Britain's Adam Peaty, who set the world record during Saturday's qualifying heat and nearly beat it again in the semifinals.

Women's Gymnastics Hit the Mat

Team USA won gold in London four years ago with a quintet that became known as the “Fierce Five.” Two members of that group are back for Rio, but before they can worry about defending that championship, they'll need to get through Sunday's qualifying rotations.

It will be an all-day affair at Arena Olimpica do Rio, with the first of five subdivisions starting at 8:45 a.m. ET and the last not beginning until 7:30 p.m. ET.

Returning standouts Gabby Douglas—who also won the individual all-around gold in London—and Aly Raisman are joined by teenagers Simone Biles, Laurie Hernandez and Madison Kocian. They're one of 12 countries that have the requisite five gymnasts needed to contend for the all-around team title, of which eight will advance to Tuesday's finals.

Biles, Douglas and Raisman will compete in all four disciplines—vault, uneven bars, balance beam and floor exercise—while Kocian will do just the uneven bars and Hernandez will do the other three.

Will U.S. Women's Basketball Continue to Dominate?

Jessica Hill/Associated Press/Associated Press

The United States hasn't lost a major international competition in women's basketball since 2006, when it took third in the world championship. Since then, it's been nothing but complete dominance, winning every game in the last two Olympics and last two world championships.

The perfect run isn't likely to end in the Rio opener, as African champion Senegal is making just its second Olympic appearance after placing 12th out of 12 teams in 2000. Still, the players aren't taking this initial competition lightly.

"We just have to know that we have a target on our backs and every single country has been preparing for the past three or four years for this opportunity to play in the Olympics," 37-year-old Tamika Catchings, playing in her fourth Olympics, told Voice of America's Greg Flakus. "We cannot just get comfortable and think we are just going to walk out on the court and automatically win."

In 2012, Team USA won its five group-stage matches by an average of 36.6 points, none by fewer than 25 points. Its opening game is set for 11 a.m. ET.

Serena Takes to the Court

ANDREW CABALLERO-REYNOLDS/Getty Images

Having rested following her 22nd Grand Slam title at Wimbledon, Serena Williams returns to action looking to defend her Olympic singles gold medal by taking on Australia's Daria Gavrilova. Gavrilova, 22, is ranked 46th in the world and reached the fourth round of the Australian Open earlier this year.

Williams will be anxious to get to action after taking to social media on Friday to voice her frustration at the many delays that came with participating in the opening ceremony. Being stuck on a bus before getting into the main stadium was getting the best of her.

"So I don't mean to be Debbie Downer or a Serena Downer, but I'm kind of ready to go, I'm really tired, I'm overwhelmed," Williams said on Snapchat (via the International Business Times' Wardah Sempa and Fiona Keating).

Williams will play two matches Sunday, later on teaming with sister Venus Williams in doubles against Lucie Safarova and Barbora Strycova of the Czech Republic in the first round. The Williams sisters are defending Olympic doubles champions.

American Men's Volleyball Aiming High

Jeff Roberson/Associated Press/Associated Press

Team USA has won gold three times in Olympic men's volleyball, most recently in 2008, but last time in London, it had to settle for fifth place. Coming off a title at the FIVB World Cup last September in Japan, though, the Americans might be playing their best volleyball ever.

The opening match of preliminary-round action comes at 4 p.m. ET against Canada.

Ten of the 12 players from that World Cup squad are on the Rio roster, including 34-year-old captain David Lee, who is appearing in his third Olympics and was part of the 2008 gold-medal squad. Most of his teammates are new to this stage, however, so he'll be passing out wisdom while trying to finish on top. 

"This is probably my last one—my last shot to climb that mountain again," Lee told the San Diego Union-Tribune's Bryce Miller. "This is my shot to go out on top. So I’m putting everything into this."

Russia is defending Olympic champion, having beaten Brazil in 2012 in London. Brazil and 2012 bronze medalist Italy are in the United States' pool.

Bounce-Back for Brazilian Soccer?

Host Brazil will look to bounce back from a disappointing opening scoreless draw against South Africa when it takes on Iraq at 9 p.m. ET Sunday in Brasilia. That match will come right after South Africa and Denmark face off in the other Group A match.

Including the 2014 World Cup, which Brazil also hosted, it is winless in three consecutive international matches on its home soil.

Only one match on Sunday features teams that both won their initial outing, with Honduras and Portugal meeting in Group D at 2 p.m. ET in Rio de Janeiro, with the winner assured of moving into the knockout stage. Consequently, if either Algeria or Argentina fall in the other Group D match, their Olympics are all but over.

Also on tap Sunday are Group B matches pitting Nigeria against Sweden and Japan against Colombia, while in Group C Mexico takes on Fiji looking for a win after tying Germany, while Germany goes against South Korea.

Follow Brian J. Pedersen on Twitter at @realBJP.