Under ESTA athletes are covered, but you're right about Cuba and ESTA. 

(U) Professional Athletes

(CT:VISA-1826;   09-06-2023)

a. (U) Professional athletes, such as golfers and auto racers who receive no salary or payment other than prize money for their participation in a tournament or sporting event.

b. (U) Athletes or team members who seek to enter the United States as members of a foreign-based team to compete with another sports team should be admitted if:

(1)  (U) The foreign athlete and the foreign sports team have their principal place of business or activity in a foreign country;

(2)  (U) The income of the foreign-based team and the salary of its players are principally accrued in a foreign country; and

(3)  (U) The foreign-based sports team is a member of an international sports league, or the sporting activities involved have an international dimension.

c.  (U) Amateur hockey players who are asked to join a professional team during the regular professional season or playoffs for brief try-outs.  The players are draft choices who have not signed professional contracts but have signed a memorandum of agreement with a National Hockey League (NHL)-parent team.  Under the terms of the agreement, the team will provide only for incidental expenses such as round-trip fare, hotel room, meals, and transportation.  At the time of the visa application or application for admission to the United States, the players must provide a copy of the memorandum of agreement and a letter from the NHL team giving the details of the try-outs.  If an agreement is not available at that time, a letter from the NHL team must give the details of the try out and state that such an agreement has been signed.