When Don Mattingly played for the Yankees from 1982-95, beards were not allowed, so Mattingly sported a mustache for most of his career. As a manager, Mattingly has been clean-shaven and the new Marlins manager won't allow any facial hair for his players.
"Guys may or may not like it," Mattingly said, via the Miami Herald. "I just think when we all get together, this is what we want and this is the way we go."
The Marlins had a no-facial-hair policy in place until 2012, when then-manager Ozzie Guillen lifted the ban, and the team has since allowed varying degrees of beards, goatees and mustaches.