If your son was 14 or so I would advise him to have a talk
with the 1st baseman, let him know he's gonna end up on
his @ss next time this happens. If he was 17 I suspect
this little discussion would have taken place already. But
he's 7. Accentuate the positive, eliminate the negative,
latch on to the affirmative, don't mess with mr. in between.
Good choice to let him play out the season, and if he asks
what's up with his friend the 1st baseman just shrug
your shoulders and give him a hug. He'll be fine