A total of 18 countries are already assured of participating, including the host nation. Curiously reigning European champions Slovenia are not among them, nor can they secure a space in the coming days.

Slovenia lie bottom of their six-team group in the second round of European qualification with two wins and eight defeats to their name. Victories in their final two fixtures cannot provide salvation to their obvious disappointment.

"To be European champions and not be in the World Cup, it’s tough," their teenage sensation Luka Dončić told the New York Times in November when their hopes were extinguished. "I don’t know why they changed it."

The change Dončić referred to was made by FIBA, who implemented a new competition calendar back in 2017 with the aim significantly boosting national team events and growing the sport.

The calendar would operate in a similar way to other team sports, such as football, where designated periods of the year would see international fixtures take place. It would ensure regular national team matches throughout the year, whereas they would previously be concentrated in tournaments at the end of the club season.

FIBA’s logic made perfect sense. The system would ensure players have the possibility to compete in front of a home crowd, whereas former national team heroes had often gone through their entire careers with only a handful of fixtures, at best, without that chance. Packed crowds would be treated to regularly watching star names from their own or opposition teams, which would help to grow interest in the sport.

The theory might have been sound, but the practice has offered mixed results.

Slovenia will feel they have been hit hardest by the change. Ordinarily their fourth consecutive World Cup appearance would already be assured, courtesy of their maiden EuroBasket triumph back in 2017.

Instead Slovenia were among the nations taking part in the new qualification process. Dončić and Goran Dragić, who was voted as the Most Valuable Player at EuroBasket, would watch their progress from afar.

Unlike FIFA windows when clubs are obliged to release players to national teams, teams in the North American-based National Basketball Association (NBA) were exempt from allowing their players to represent their nations in the FIBA World Cup qualifiers. EuroLeague, the top-tier club competition in Europe, opted to follow suit.

Shorn of their star names, Slovenia subsequently struggled in qualification. Their absence from the World Cup have prompted criticism of FIBA from some quarters, with fans bemoaning the loss of Dončić from the tournament. It follows the 19-year-old having established himself as one of the next generation of NBA stars, with the Dallas Mavericks player considered unfortunate to have missed out on All-Star honours this season.

To add further salt in the wound, the FIBA World Cup will help to decide Olympic qualification. It leaves Slovenian hopes resting on a wildcard invitation to one of four final Tokyo 2020 qualification events.

The European champions are not the only ones impacted by the new calendar, with Olympic and Eurobasket silver medallists Serbia still yet to secure a World Cup berth. A victory in one of their final two fixtures would prove enough to do so. Qualification has proved something of a struggle, with six wins and four defeats so far.

Serbia have notably been without the Denver Nuggets’ Nikola Jokić throughout the entire qualification process. In fact, his last appearance for the national team came in the final of the 2016 Olympic Games in Rio de Janeiro. It has not gone unnoticed.

A tweet calling for Serbian fans to vote for the centre to be included in the NBA all-star game was met with a mixed response. Amid the positive responses, came replies asserting they would only vote for Jokić when he is seen in a national team jersey again.

Occasionally a helping hand is required. Serbian coach Aleksandar Đorđević was able to call upon the services of NBA players Bogdan Bogdanović and Nemanja Bjelica on occasion in qualifying. Their NBA team, the Sacramento Kings’ general manager Vlade Divac happens to be a former Yugoslavian national team-mate of Đorđević.

While Serbia look on course to seal a World Cup place, their neighbours Croatia could count the cost of key absentees and go the way of Slovenia.

The situation has led to suggestions that rather than the best teams qualifying for the World Cup, it is those best equipped to cope with missing stars who have benefited. Nations such as France and Greece have enjoyed a trouble-free qualification, despite missing players. Several fans have opined that nations with less depth are effectively being punished for their stars playing in the NBA or EuroLeague.

The absence of players from the latter has irked FIBA to the extent International Olympic Committee President Thomas Bach mentioned the situation when calling for the European Sport Model to be defended. The German claimed in November that the EuroLeague "intrudes into the work of European basketball and makes it almost impossible to organise national team events".

FIBA President Horacio Muratore claimed to have been surprised by the EuroLeague’s position in December.

"We tried to work together and from the start they said, 'No'," he said. "We wanted to build, not to take away from anyone. I cannot understand how, some of Europe's biggest clubs, who allow their football players to join their national teams, don't do the same with basketball. They're the same club."

FIBA certainly had a point after the EuroLeague, which is 11 of the 16 competing clubs, opted not to include a break for the international windows when announcing their calendar back in 2017.

The move was viewed as an escalation of an existing dispute with the governing body over the European club game, which began when the EuroLeague broke away from FIBA in 2000. FIBA Europe’s establishment of a Basketball Champions League in 2016 viewed as an effort to wrestle back control over the European club game. They also had hit out at how most teams’ participation were not based on sporting merit, with 11 clubs have long-term licences. The format certainly carries a similarity to proposals of what a potential European Super League in football could become.

The EuroLeague’s opposition was certainly strengthened by the NBA being exempt from the calendar rules.

Both FIBA and the EuroLeague filed complaints to the European Commission against each other, which were later dropped.

A solution to the calendar dispute has yet to be found, highlighted by both World Cup qualification and EuroLeague matches being held on the same day in November. With attention split, the clash was evidently a bad thing for both.

There has been support for FIBA’s idea as fans have been able to watch their national teams on a regular basis, with the governing body reporting sold-out qualifiers in Asia, Africa, Europe and the Americas.

The absence of stars has led to suggestions that the quality of the product offered has been diluted. A National Federation president was quoted last year as claiming the ticket sales and sponsorship had been impacted by the lack of top names.

Opportunities have certainly been presented to young players, yet this has led to concerns that developmental teams are effectively trying to secure World Cup qualification.

There is also no guarantee the players who have punched their nations ticket to the World Cup will even travel to China. The extreme case comes with the United States team, with players from the NBA’s development league having played the country’s qualifiers. They will make way for more established names in the summer.

Greece’s Giannis Antetokounmpo is among the NBA players who have declared that they will play at the World Cup.

There are clearly positive and negatives in the current system, while FIBA and the EuroLeague both appear to have sound points in their dispute as they both seek the same objective of growing the sport.

FIBA appear set to continue with their calendar in the future, with recently appointed secretary general Andreas Zagklis claiming there have been positive numbers from qualifiers to show the growth of the sport. He expressed his hope earlier this month that a solution could be found to benefit all parties and boost basketball's development.

"At some time, we will sit on a table and must find solutions in a couple of things," he said, according to EuroHoops. 

"The balance between the clubs and the competitions they participate and national teams’ tournaments. This is the only way and that’s how the ‘pie’ will be larger and become enough for everyone."