His answers are not so clear as the 2016 games in Rio de Janeiro inch closer. The most decorated Olympian of all time has participated at every opportunity for the past 14 years.
The 22-time Olympic gold medalist went to watch the 2013 FINA World Championships in Barcelona, where he cheered on his former competitors.
A commentator asked him whether the door was closed, and he joked about a temporary break from golf as he suffers from an injury bad enough to put him in a walking boot. He did not give a firm no regarding his return, however.
He did say that he does not miss the nerves of having to compete, but Phelps said he has not been to a swimming competition since 2012, when he was competing in London just before he announced his retirement.
Five-time Olympic champion Ryan Lochte said he would be thrilled if Phelps returned.
"He was the hardest racer I have ever had to go up against," Lochte said. "I had fun and we have grown to a really good friendship because of that."
Phelps' former coach Bob Bowman does not think there is a chance he will return, however.
"My answer is always, when I see it I'll believe it but there is no indication at this point," said Bowman. "I think that is where we will leave that one."