Is it mandatory for MLB players to wear a ball cap while on defense?
Could the walk out on the field with nothing on their head? Its a silly question but I want to know.
yes, it is. It is required that big leaguers wear some sort of cap of their head, batting helmets are allowed too. Dave Parker, Dick Allen and John Olerud are three men who wore helmets on defense for various reasons (Parker and Allen so they don’t get hurt by crap thrown at them by fans, Olerud because of a brain problem). In addition to wearing a cap, they are also not allowed to wear them backwards or at a 90 degree angle too.
Snapback Hat Restoration: How to wash your hats- Ball Cap – Buddy