Possibly the new exemplar for timeliness-based (as opposed to funniness-based) casting. Sure, he's the fastest human around in the water, but whoever thought that Phelps who stumbled multiple times while trying to read his cue cards could deliver on dry land should swim ten laps in the pool of shame.
Top 10 Dubious SNL Hosts
They can't act or sing but can they take a joke? What happens when Saturday Night Live's guest stars go bad