The top two finishers in all 26 events at the U.S. Olympic Swimming Trials will clinch Rio berths, which means Olympic and/or World champions will be left out of the exclusive team.
Michael Phelps, Ryan Lochte, Missy Franklin and Katie Ledecky headline the meet in Omaha, Neb., beginning Sunday.
While they are favorites to make the Olympic team, they will be joined by many more Olympic medal threats.
For relays, the top six finishers in the 100m and 200m freestyles are in line to to make the Olympic team, too.