Puig quickly joined in and made everyone's day, per TMZ Sports:
Once the team, the coaches and parents realized who he was (they recognized him instantly) ... the place went crazy and let Yasiel run the practice.
We're told Puig spent 30 minutes signing autographs for everyone -- bats, gloves, hats, shirts, etc. -- and then took the mound and pitched while the kids took turns at bat.
We spoke to one of the parents who tells us, "It's a practice the kids will never forget."
Puig often looks like a big (and ridiculously athletic) kid while playing anyway, so this makes perfect sense.