Pedro Gomez explains what Cuba's changing relations with other countries mean for MLB players and others who defected from the country. (2:46)

Relations between the U.S. and Cuba have moved closer to being normalized, a point that will be further underscored Tuesday when the Tampa Bay Rays play the Cuban national team in Havana.

So everything must be open, right? Well, no. At least, not yet. But there are definitely signs indicating change -- real change -- could be forthcoming.

Cuban baseball players must still defect to have the opportunity to play in the major leagues, and that remains a thorny issue for Major League Baseball and the MLB Players Association. The defections of the Gourriel brothers, Yulieski and Lourdes, last month signaled how nothing has really changed.

"If we could make a deal to resolve this problem, it would attract a lot of attention,'' MLB commissioner Rob Manfred said. "I can't say we are close. It's a very uncomfortable position for us to be in. I am comfortable in saying that we, the clubs and Major League Baseball, are at the end of this pipeline. The economics are what they are and we are at the end of this. However, we are not controlling what is happening."

But just last week, President Barack Obama's administration announced new rules that would allow Cuban citizens to be paid for working in the U.S. In essence, the measures are a huge setback for those who want to strengthen the trade embargo, and they apparently open the door for baseball players to play for big league clubs and keep their money without defecting from Cuba.

But there's one glaring question: Are Cuban baseball players free to leave, or do they still belong to the Serie Nacional, the Cuban baseball league, and therefore are not free to leave their teams in Cuba?

Livan Hernandez, left, and his brother, Orlando "El Duque" Hernandez, combined to win five World Series titles after defecting from Cuba. Louis DeLuca/MLB Photos/Getty Images

The question, which has yet to be answered, is part of the entire mess that has engulfed Cuban players since the U.S. embargo was put in place in 1962. But it wasn't until the past 10-15 years that Cuban players have so openly decided to defect and test their skills at the big league level. The list of defectors is impressive: brothers Livan and Orlando "El Duque" Hernandez, Rey Ordonez, Aroldis Chapman, Yoenis Cespedes, Yasiel Puig and Jose Abreu have highlighted the list.

"It was the most difficult decision I have ever had to make,'' said reliever Danys Baez, who defected in 1999, signed with Tampa Bay and went on to pitch 10 years in the majors. "For anyone to think that leaving behind your family and your native country without knowing if you could ever go back is an easy decision, try it."

And that doesn't even begin to mention the perils involved. First and foremost, the players must deal with human traffickers, who have orchestrated several defections and are sometimes part of extremely dangerous cartels. One current big league player, who chose to remain anonymous, who defected a few years ago says he will be on the hook for payments to a cartel throughout his major league career.

"As much as anything, it's a very challenging and sensitive issue," MLBPA director Tony Clark said. "But on the other hand, I think everyone involved has the same concern -- affording everybody their dreams of playing in the majors safely. But there remain a lot of hurdles, both political and personal.''

A major issue is that there are four entities trying to negotiate change so baseball players can move about freely -- Major League Baseball, the players association, and, most important, the U.S. and Cuban governments.

It remains to be seen what system will be implemented so Cuban players can sign with big league clubs. Will it be a posting system, similar to how Japanese players are allowed to sign with major league clubs? One significant difference is that Japanese players are the property of private Japanese-owned clubs. In Cuba, there are no privately-owned clubs. The state owns and runs the entire Serie Nacional.

Tuesday's exhibition game is the first involving a MLB team in Cuba since 1999, when the Baltimore Orioles played the Cuban national team in a home-and-home two-game series. Nothing came from that historic visit. The belief now is that this Rays' visit could signal real change and possibly lead to future games in Cuba, including ones involving two major league clubs.

There also exists the possibility of a combined Cuban roster, taking players who have defected and those remaining on the island to create a unified team for next year's World Baseball Classic.

"If that were to happen, I think I know who would be champions,'' said legendary Cuban pitcher Pedro Luis Lazo, who has won Olympic and international gold medals and was part of the inaugural WBC in 2006. "It would definitely be our Cuban team."

A state department source said President Obama's ideal plan is to have the thawing of relations progress so far that the next president won't be able to reverse whatever changes are in place by January of next year.

While no one involved is naïve to say baseball is the primary thrust behind the lax rules between the two countries, there is also a faction that believes baseball could be a driving force behind the government's efforts to bridge their differences.

"I would propose, how crazy was it that ping-pong played a role in opening China?'' Manfred asked. "We try and find common themes and commonalities, and baseball has that between the U.S. and Cuba."