Shannon Millers world record for the 100m freestyle is already broken and the gymnast from South Dakota has made it her goal to beat it.
Millers Olympic debut on Saturday night will be the first of four shows in four months for the American Girl gymnastics team.
Her first is a meet in Portland, Oregon, against the US team that beat Japan in the world championships.
It will be a rematch of the meet from March 23, when Millers made history by winning the 100 metres freestyle.
Millars best moment came in the womens semi-final in Barcelona when she scored a huge win in the 200m freemestyle.
Her second match is against a US team, the defending Olympic champions.
The American team has only been to the Olympics once since 1952 and is unbeaten at Rio de Janeiro.
Millard won bronze at the Athens Olympics in 2012 and then won bronze in the final of the 2016 Games in Rio de Janiero, where she was named Olympic champion.
The two-time Olympic champion will take on American Gwen Carr in the first match on Saturday, the fourth show in four.
A third show is on June 14 in Edmonton, Canada, when American Team USA will face off against the USA team.
Millards first meet with the American team will be in Portland on May 15.
The US team has already won gold at the London Games in 2020 and silver at the Rio Olympics in 2016.