Here's a baseball themed Spidey Super Stories short from the original Electric Company. Spider-Man (Danny Seagren) attends a Mets game at Shea Stadium, but the defending NL champs have to also deal with The Wall. Series regular Skip Hinnant plays a Mets outfielder, while Morgan Freeman is the umpire. Does sound like Morgan unwittingly did a Scatman Crothers mimic.
Not one of the better ones in the series. The producers couldn't come up with enough cheddar in the budget to actually replicate even a portion of Shea Stadium. When the series was revived several years later, Sesame (formerly Children's Television) Workshop, despite the fact that Marvel Comics and some of the Muppets are now Disney property, couldn't reach a deal with Disney to revive this feature, even with today's advanced technology. Their loss.