AP National Writer
CHARLOTTE, N.C. (AP) -- Michael Phelps is off playing golf and showing no signs of backtracking on his decision to retire from swimming.
That leaves a big hole on the U.S. team as it prepares for the world championships this summer and begins looking ahead to the 2016 Rio Olympics.
But don't think the Americans are suddenly going to be just another country at the pool. While there's certainly no replacing the winningest Olympian ever, the U.S. has plenty of top swimmers back from its London team, including Ryan Lochte, Missy Franklin and Allison Schmitt.
Also, there are some top prospects on the horizon, such as teenagers Ryan Murphy, Lia Neal and Kevin Cordes.
"It's time for other people to step it up," said Lochte, an 11-time Olympic medalist who plans to keep swimming at least through the Rio Games. "We've been dominant for years and years, and we're going to keep that tradition alive."
The next big meet is this summer's world championships in Barcelona, where the Americans figure to have plenty of star power even without Phelps.
On the men's side is Lochte, who won five medals in London and recently resumed full-time training after wrapping production of his reality television show. While admittedly not in the best shape, which was evident from his lackluster performance at the Charlotte Grand Prix this past weekend, his passion for swimming hasn't waned a bit.
"As long as I'm stepping on the blocks, I'm going to race," Lochte said. "Throughout these Grand Prix meets, I've been getting a little better. I still have two more meets after this (in Canada and California) to really work on the little things before world trials. A month ago, I was a little nervous. But now, I'm feeling better."
The women, meanwhile, figure to be led by their two biggest stars from the last Olympics, Franklin and Schmitt.
Franklin just turned 18 and is finishing up her senior year of high school in Colorado. After her remarkable performance in London, where she swam in seven events and claimed five medals, there's no doubt that she's most likely to fill much of the void left by Phelps.
The vivacious teenager is eager to take a leadership role on the national team.
"Being able to go the Olympics and (2007) world championships has given me some awesome insight," she said. "I'm always going to be there for my teammates if they have a question or need some help or just need someone to tell them, 'It's OK. Don't worry. Don't be intimidated. You're going to do great.' That's what I'm here for. That's my job now."
Not that she expects to match Phelps' performance in the pool. After all, he won more gold medals (18) and total medals (22) than anyone in Olympic history.
It will be tough for any swimmer, even one with Franklin's immense talent, to take such a dominant role on the American team. The key now is to develop more depth in the program so the overall production doesn't slide.
"It's impossible to replace Michael Phelps. No one will ever replace him," Franklin said. "But it's incredible to have so many great young swimmers coming up."
Franklin plans to remain an amateur for two more years while swimming at the University of California, then turn professional a year before the Rio Olympics. Schmitt also passed on the chance to cash in on her performance in London, where she won three golds and a silver, returning for her senior year at the University of Georgia.
After leading the Bulldogs to the women's national championship, the 22-year-old finally turned pro before the Charlotte meet. She's also resumed training with Bob Bowman, who was Phelps' longtime mentor and will be leading the U.S. men's team at the world championships.
Going back to college was the right move for Schmitt, who hopes to start challenging in the 100 freestyle after competing in the 200 and 400 free in London.
"It was definitely a different atmosphere," she said. "People say the Olympics are a high, and I had trouble coming back down from them. But having the team there for me, supporting me the whole way, and jumping back into the college season definitely helped me out a lot."
Murphy hasn't even gotten to college yet, but he's already one of the rising stars for the next Olympic cycle.
Only 17, he challenged for a spot on the 2012 team, finishing fourth in the 200-meter backstroke and sixth in the 100 back at last summer's U.S. trials, where the top two finishers made it to London. Now a senior at Bolles High School in Jacksonville, Fla., Murphy expects to keep progressing in the back -- his best stroke -- and could become a factor in both freestyle and butterfly by the time of the Rio Games.