Sportscaster Jim Nantz appeared on 'How I Met Your Mother' as a figment of Barney's imagination. Technically, this does count towards his League of Themselves appearances in Toobworld because it acknowledges that he does exist in the TV Universe. Otherwise, how could Barney have dreamed him up?
Not that it actually matters, however. Nantz already has enough appearances as himself in TV shows to qualify for membership in the TV Crossover Hall of Fame. And (not so) suprisingly, they're almost all CBS shows: 'Arli$$' (the one ringer in the bunch), 'Yes, Dear', 'Criminal Minds' and three episodes of 'Clubhouse'
It also puts Nantz into a category in which celebrities appear as themselves in visions, dreams, and fantasies of TV characters - Oprah, Sinbad, Rob Thomas......
Nick Swisher of the New York Yankees was also in the episode last night, but he was actually there in McLaren's Bar. (That's him in the booth to the far left. He apparently stole Astro Boy's haircut....)