He said he has been playing phone tag with actor/comedian Ashton Kutcher, looking for advice at being funny - he met Demi Moore, Kutcher's wife, at the MTV awards, and Moore told Phelps that Kutcher could help him.
SNL creator and producer Lorne Michaels predicted Phelps would draw laughs on the show and joked, "No matter what happens, they can't take those medals away." Michaels added, "He's not suddenly going to be a professional sketch player, but he'll do just fine."
Even if Phelps is only after more endorsement deals or eventual commentator gigs, talent pros say he will most definitely need to refine his style.
And he'll have to work at it, the way he logged hours perfecting his starts, turns and dolphin kicks, says Dan Weedin, a Seattle-based speech coach who has worked with the Seattle Sonics and Storm men's and women's pro basketball teams.
"Olympic champions like Michael Phelps must realize that in order to be as successful in speaking, they need to put in the same amount of training that they do for their sports," Weedin says.
"Being able to connect with an audience takes strategy, planning and plenty of practice with a mentor or coach."
Based on what he has seen of Phelps so far, Weedin approves of his laid-back, relaxed style. He thinks Phelps comes across as someone people want as a friend.
But he'd advise Phelps to throw away the flip-flops and hoodie he wore on Leno. Then Weedin would help him lose his habit of larding sentences with "uh" and "you know."
"I would love to see him take the Michael Jordan approach and dress for the show," Weedin says. "For a talk show, he'd do better to at least be in business casual - a dress shirt, no tie, maybe a jacket. That comes with someone mentoring him."
As a swimmer, all Phelps had to worry about was getting to the pool and swimming the fastest. But celebrity invites scrutiny.
Blogs erupted with critical chatter after Phelps' appearance on the MTV awards. Mercy for a newcomer apparently isn't part of the equation.
The Associated Press said Phelps spoke so low that no one could hear him. An Australian Web site thought the swimmer's choice of a black jacket, white shirt and jeans lacked "any sense of style." And someone typed on the Web service Twitter: "Phelps not very good at reading a prompter. Could this spell disaster for his SNL hosting gig next week? Uh oh!"