Nic Fink's breaststroke leg will be paramount for the US to repeat as champions in the mixed 400 medley as the US attempts to hold off a resurgent China.
Defending World Champion Mollie O’Callaghan is the only returning medalist racing this year, leaving the podium wide open for some new faces to step up.
The three fastest performers in history are all set to go head-to-head for the first time since Canadian teenager Summer McIntosh fully burst onto the scene.