INDIANAPOLIS (AP) — The American world championship rosters will have a very different look this summer.

It's something even the veteran swimmers acknowledge will take some getting used to.

Of the 24 women who qualified for the U.S. team competing in Barcelona next month, 15 won't turn 22 until after the meet. Seven are teenagers. And of the 25 men on the roster, 12 have never been to an Olympics, 11 are 23 or younger and five of those are teens.

Change has become a traditional way of life in the swimming community in post-Olympic years. But with so many key leaders missing and so many of last year's Olympians still trying to get back in shape, the future stars of American swimming seem ready to prove themselves now.