Of them, you'll note, over a third have first names starting with the letter Y. Those ranks will increase in 2015, as the Diamondbacks signed Cuban outfielder Yasmany Tomas to a six-year, $68.5 million contract this week. That'll make six Cuban players with a first name starting with Y. In 2014, the only players appearing in 50+ games with a first name starting in Y that were not Cuban were Mariners reliever Yoervis Medina, Yankees/Padres third baseman Yangervis Solarte (both from Venezuela), Indians catcher Yan Gomes (Brazil), and Cardinals catcher Yadier Molina (Puerto Rico).
It turns out there's a reason. As this article explains,
...the preponderance of names starting with the letter Y may reflect the contact Cubans had with Russian advisers sporting names like Yuri and Yevgeny in the years when the Soviet Union was bankrolling Castro's revolution.That probably explains the Y-names for Medina and Solarte, both hailing from socialist Venezuela. That's also why the Cuban player who saw the most playing time this season, Alexei Ramirez, has a name you'd associate more with Russian than with a Spanish-speaking island.
So there you have it. Cuban ballplayers have first names starting with the letter Y because their parents wanted to pay homage to the USSR.
Sorry, that's all I've got for now. You'll have to find something else to read while you're standing in the checkout line at Target.