please help me

I have all these shows on home made DVD's and been watching them (and writing GAMM fan fiction forever --I was eleven when the show first was on the air) and I can safely say there is no scene in any episode like the one you describe.

There was an episode where the little boy (Jonathan, by the way) was having trouble trying out for the local baseball team, (the Schooner Bay Oysters) and Captain Gregg "helped" him by causing crazy things to happen until Jonathan told him to stop it, because he wanted to do it himself.

There was also another episode where Jonathan hits a pop fly and breaks a window on the second floor. Captain Gregg comes out on the balcony holding the baseball as Mrs. Muir is saying something to the effect that "since it was your first home run, we'll forget it this time, but try to be more careful" and he retorts as he holds up the baseball "We will NOT forget it, Madame -- this ball went right through my head!"

But these are the only two baseball references.