Regardless of whether they were born in states or Puerto Rico, they are U.S. citizens and are eligible for the U.S. team.
FYI: “states” is not capitalized when referring to individual states in the U.S. unless it is part of a proper noun or the beginning of a sentence. For example:
• “The states of California and Texas are very populous.”
• “The United States has 50 states.”
However, when referring to a specific state’s full name, the name of the state itself is capitalized:
• “California is a state on the West Coast.”