There has a been a few deaths and about a dozen births of former Major League players. I will elaborate on a couple Leap Day births.
Martin was a key member of the Cardinals' Gashouse Gang that won two World Series titles (1931 and 1934). Martin has a MLB best career World Series batting average of .414. Martin's other accomplishments include leading the league in stolen bases three times and playing in four All Star games.
After his playing day, Rosen worked in the front office. His work as a General Manager for the San Francisco Giants led him to being named Executive of the Year in 1987. To this day, Rosen is still the only person ever to win the MVP and Executive of the Year honors.