The Diamond League's second competition of the year boasts several highly anticipated Rio rematches on Saturday in Shanghai. Between Elaine Thompson in the 100m, Omar McLeod in the 110m hurdles, Shaunae Miller-Uibo in the 400m, and David Rudisha making his season debut in the 800m, Shanghai is poised to be another must-watch Diamond League competition.

Women's 100m

With three Olympic champions, three world champions, and two world medalists headlining the field, the women's 100m looks to be the deepest field assembled in Shanghai.

The most recent Olympic 100m champion, Elaine Thompson, will compete after running a 200m season debut of 22.19 to win the Doha Diamond League meeting. The performance is just 0.03 slower than the Jamaican sprinter's 2016 season debut at the Prefontaine Classic, the same season in which she ultimately won Olympic gold in the 100m and 200m in Rio. Thompson will be challenged by Olympic silver medalist Tori Bowie, who earned silver in the 100m and bronze in the 200m at the 2016 Olympic Games. Bowie has only raced three times so far this season, and her most recent run was a world-leading 22.09 in the 200m at the Tom Jones Memorial in Gainesville, FL.

Fellow American and Olympic long jump champion Tianna Bartoletta will be competing after running a 100m season opener of 11.08 at the Bryan Clay Invitational. Jamaican sprint legend Veronica Campbell-Brown will also be competing after finishing fifth in the 200m at the Doha Diamond League meeting. The 34-year-old has three Olympic gold medals, five world titles, and a total of 20 international championship medals to her name. Murielle Ahoure, Michelle-Lee Ahye, and Christania Williams will also be competing, and all three competitors also raced in the 2016 Olympic 100m final.

Men's 200m

Nineteen-year-old sprint sensation Noah Lyles will be competing in his first Diamond League competition of his career. Lyles turned professional after finishing fourth in the 200m at the Olympic Trials last summer. His mark of 20.09 broke the American junior record and narrowly missed making the Olympic team by 0.09 seconds. During the indoor season, Lyles won the 300m in an American record time of 31.87 at the USATF Indoor Championships.

The 200m competition will be fierce with several American sprint greats in contention, including 2008 Olympic 400m champion LaShawn Merritt, 2016 Olympian Ameer Webb, and two-time world champion Wallace Spearmon.

Men's 800m

World-record holder and two-time Olympic champion David Rudisha will be making his much-anticipated season debut against a strong 800m field in Shanghai. The last time Rudisha raced was a 1:43 victory at the ISTAF meeting in Berlin after defending his Olympic gold medal in Rio. Saturday will be Rudisha's first race of 2017 and his first test of fitness in preparation for the World Championships in London.

He will be joined by fellow Kenyans Ferguson Rotich and Alfred Kipketer, who both competed in the 2016 Olympic 800m final.

Cas Loxsom, the lone American in the event, will also be running in his first Diamond League meeting of the year after running a 400m at the Payton Jordan Invitational. Earlier in the season, Loxsom broke the 600m indoor world record with a 1:14.91 performance.

Men's 110m Hurdles

The men's 110m hurdles will be a showdown between young and veteran hurdle greats. Defending Olympic champion Omar McLeod will toe the line after winning the Drake Relays in a world-leading 13.04. He will be challenged by 2012 Olympic champion and world-record holder Aries Merritt, who is competing this season after a valiant return to the track in 2016 which followed kidney transplant surgery. Olympic silver medalist Orlando Ortega will take on the Olympic champions after clocking a seventh-place finish in the 60m hurdles at the European championships.

David Oliver, the 2013 world champion, will be opening up his season after a 2016 which included a heartbreaking hamstring injury in the rounds of the Olympic Trials. Oliver returned to health later in the summer and notched two more performances. Hansle Parchment, the 2015 world silver medalist, is set to take on the field after opening up his season with a runner-up finish at the Utech Classic in his native Kingston, Jamaica. And finally U.S. Olympian Jeff Porter will compete after notching a season's best of 13.53 in Greensboro on April 14.

Men's Pole Vault

The men's pole vault will be a showdown between the defending Olympic champion, the 2012 Olympic champion, the 2015 world champion, and the 2016 Olympic bronze medalist. Thiago Braz of Brazil will be competing in his first outdoor meet since claiming Olympic gold in his native Rio last summer. His rival, 2016 Olympic silver medalist and 2012 champion Renaud Lavillenie, will also be competing in his first outdoor competition this year. Olympic bronze medalist Sam Kendricks will round out the Rio podium rematch set to take place.

Shawn Barber will also be competing in his first Diamond League competition this year after posting a season's best of 5.83m during the indoor season. Barber recently came out publicly as gay with a Facebook announcement that read, "Gay and proud! Thank you to my parents for being such a great support. I continue to grow as a person and have a great support group. My parents are my greatest support and have helped me through a lot recently. To my friends, you are always my friends and I love you too!" The 2015 world champion and NCAA record-holder is one of the most prominent openly gay athletes in the world.

Women's 400m

Defending Olympic 400m champion Shaunae Miller-Uibo will toe the line in her first Diamond League meet and open 400m of 2017. The performance follows a stunning relay performance at the IAAF World Relays in which Miller-Uibo split 49.60 on her 400m leg to help the Bahamas win the mixed relay competition.

She will be joined by U.S. 400m mainstay Natasha Hastings, who has earned two Olympic gold medals as a member of the 4x400m 2008 and 2016 relay teams. Hastings recently contributed to the United States' runner-up finish in the 4x400m at Penn Relays.

Follow along with live updates of the Shanghai Diamond League competition this Saturday.