The US will go with Simone Manuel, Abbey Weitzeil, Dana Vollmer and Katie Ledecky in the 400 free relay Saturday night. Ledecky's inclusion would have been considered a surprise a week ago but now she's swimming the anchor leg after a :52.64 in prelims earlier Saturday. Vollmer will swim a challenging double with the 100 fly semis scheduled a little more than an hour before the relay. The US has medaled in the event in every Olympics since 1984. It most recently won bronze in London in 2012. The combination of Lia Neal, Amanda Weir, Allison Schmitt and Ledecky had the second-fastest time in prelims behind the Australians earlier Saturday.