Michael Phelps no longer is denying the possibility of a comeback. That doesn't mean that the comeback is in full swing.

The world's most decorated swimmer told the Baltimore Sun that he couldn't complete a 400-meter race in the current shape he's in.

Rumors have skyrocketed the past week that Phelps' return to competitive swimming is imminent after reports surfaced that he entered the U.S. drug-testing program for international competition on Nov. 6. Phelps has won a record 18 gold medals and 22 medal overall during three Summer Olympics competitions and would have a little more than 2 ½ years before the 2016 Rio de Janeiro Olympics.

He will be 31 when the next Summer Games begin.

The Sun reported that Phelps recently attended a swim meet in which his roommate Conor Dwyer competed. Dwyer was part of the gold medal-winning 4x200 freestyle relay at the 2012 London Olympics.

"(Dwyer) swims the (400-meter IM); that's too long," Phelps told the Sun. "I can't do that. I literally don't think if I jumped in the water right now, I could finish a 400."

He also indicated that he gets in the pool a couple of times per week, saying "I am trying to get back into some kind of shape, for myself."

Not exactly the regimen, nor the attitude, of an Olympic hopeful who eats, sleeps and breathes training in preparation for the biggest competition of their lives.

Of course, Phelps' situation is different because of the success he's already had. But that success also could play a role in how serious a comeback attempt he makes. Phelps obviously lacks the desire that any first-time Olympian would have and would need to draw on a different inspiration to make the commitment he originally had to be the best swimmer in the world.

So while he has re-entered the drug-testing program, that gesture, as of now, represents only a "going through the motions" commitment toward a comeback.