The news that Michael Phelps was returning to the pool with an eye toward possibly participating at the 2016 Summer Olympics was greeted with a big yawn by fellow swimmers.

While Phelps's un-retirement did indeed create a flurry of excitement in social media, those who know him best were not shocked by Monday's announcement.

"I wasn't surprised," 17-year-old Olympic champion Katie Ledecky told Reuters in a telephone call after a workout at her swim club in Bethesda, Maryland.

"The swimming world has known for a while that he's been training the past year so it wasn't too big of a surprise. I'm definitely excited that he's going to swimming in Mesa."

Phelps, the most decorated Olympian of all-time with a total of 22 medals, has not competed since the 2012 London Games. The Baltimore native will headline an April 24-26 meet in Mesa, Arizona, with fellow Olympians Ledecky and Ryan Lochte.

The 28-year-old, 18-time gold medalist returned to the U.S. Anti-Doping Agency registry over nine months ago and has been subject to out-of-competition testing.

Dara Torres, a winner of 12 Olympic medals, said she knew all along that Phelps would return to the pool.

"I just kind of giggled when I heard the news," she told Reuters on Tuesday via telephone from her Boston home. "I knew it. I just knew that was going to happen."

Phelps is entered in the 100m freestyle, 100m butterfly and the 50m butterfly at the Mesa event, the fourth stop of USA Swimming's 2013-14 Arena Grand Prix Series.

Torres, who won her medals over five Olympics and missed out on a ticket to the 2012 London Games by nine one-hundreths of a second in the U.S. trials, is convinced Phelps misses competing.

"I have never seen anyone as competitive as me except for Michael Phelps," said the 47-year-old Torres. "I am so competitive it's ridiculous. You have someone like Michael and now he's in the real life. He's playing golf, he's doing things here and there.

"But it's not the same as something you've been doing your whole life. For me personally, I missed the sport. I love the sport. But most of all I missed competing.

"If you're a very competitive person, it's very tough to let that go."

Torres, who competed against swimmers half her age as her career wound down, believes Phelps will have to adjust his training on the road to the 2016 Games in Rio de Janeiro.

"All the years he never took a break, it's going to be different for Michael," she said. "As far as recovery goes, it's going to be different but as far as him doing his best times, I don't think his age will be a factor.

"It's human nature, that your body is used to doing something at a certain level when you're younger. The biggest thing for me, mentally, was understanding that I can't do what I used to do training-wise.

"The hard part is knowing you can't do what the young kids are doing. You're older, you don't recover like you used to."

Ledecky is convinced Phelps will be "focused and give it all he's got."

"It should be fun to see what he can do," she said. "No matter what he does, he's already accomplished so much anything extra will be amazing to see."