Ledecky has won three titles at this week's American qualifying meet for the worlds, set for July 14-30 at Budapest, Hungary.
Because Ledecky is already on the team, she can be named to join the US champion as the second entrant in the event for the US World Championships squad.
Since she set the world record of 15:25.48 at the 2015 worlds in Russia, it would be a stunner if she weren't chosen for the spot.
Ledecky added the 400 free title on Friday to her 200 and 800 crowns for a 13th career American title. Her winning time of 3:58.44 was the fastest in the world this year by almost four seconds.
"I felt pretty controlled," Ledecky said. "Just getting out there and putting together a good swim, and feeling good throughout the whole thing made me really happy. I've always tried to have that consistency.
"I haven't really set time goals for this year. I just want to put together good swims and have some fun with it."
