- US superstar Michael Phelps came out of retirement because he believes he can swim faster than ever before, his coach Bob Bowman said on Wednesday.
Phelps, 29, admitted he was feeling "rusty" after some elementary errors at this month's US Championships, where he finished winless.
But Bowman said Phelps was driven by the conviction that he can exceed the performances that brought him 18 Olympic titles, the most achieved by any athlete.
"That's the reason he (Phelps) came back," Bowman said at the Pan Pacific Championships in Australia, Phelps's first international meet since ending his 20-month retirement in April.
"If he didn't think he had the chance to get faster I don't think he would have."
Bowman said Phelps needed to "get back into racing speed and the pressure -- he just needs more experience with that".