Keith Hernandez

From Muppet Wiki

Keith Hernandez (b. 1953) is a former Major League Baseball player. He is now a baseball analyst working for the New York Mets, for whom he played from 1983–1989.

Hernandez appeared in the Sesame Street, Special where he sang in a Celebrity version of "Put Down the Duckie" with Mookie Wilson. He also appeared in Season 19 with Mookie where the duo play Baseball with The Count.