Both Cubans and Americans have restrictions on travel, you cannot travel from the USA to Cuba and vice-versa. I as Canadian can travel to Cuba, and I have, also Cubans can travel to Canada freely.

Most if not all the current Cuban ballplayers playing in MLB have "defected" through 3rd party destinations Mexico or Canada. It's why Randy Arozerena can play for Team Mexico as a Cuban his passport is probably from Mexico or its possible someone in his family is from Mexico. So basically when one decides to do this they're leaving behind all their family and friends due to these restrictions.

If the United States would lift the embargo on Cuba this wouldn't be necessary.

LoL the whole event is being held in Qatar and built on the backs of slave labour with FIFA doing nothing about it.