The 2022 Winter Olympics may have to be rescheduled in order to accommodate football's World Cup in Qatar, say Europe's top football clubs.
It is expected that the World Cup will be moved from summer to winter in 2022 to avoid high temperatures in Qatar.
"[The Games] haven't been awarded yet," European Club Association vice-chairman Umberto Gandini told the BBC.
"I don't see why we should worry about something that is not there yet and if they can also change the dates."
Sepp Blatter, president of world football's governing body Fifa, has suggested a switch to November and December 2022 is almost inevitable.
However, that would shut down the European leagues for eight weeks, and the ECA remains unconvinced by that option.
Another possibility is to stage the tournament in January and February, although Blatter has assured the International Olympic Committee that the World Cup will not clash with the 2022 Winter Games, scheduled for February.
Blatter is an IOC member and it is thought that any disruption to the 2022 Games could jeopardise football's status as an Olympic sport.
AC Milan director Gandini represents the 200-member ECA on a Fifa panel which is seeking ways to avoid playing in the desert heat of June and July 2022, and which met for the first time in Zurich last month.
"As a European view, the first reaction was 'if we have to move it, January/February is the best option', because it will have a reduced effect on the European game because many of the leagues are on winter breaks; it would make things a a little bit more logical," he said.
"It's not impossible for the Winter Olympics to shift over 15 days for example - so if we're going to find a solution it must be not just for the football world but for the sporting world."
Among the other events that could be affected is the 2023 Africa Cup of Nations.
It is due to be held in Guinea in January and February 2023 but it would be very difficult to do so if the 2022 World Cup was moved to November and December, although switching the World Cup to the start of the year would leave the way clear for the African tournament to go ahead as scheduled.
The 2022 Winter Olympics will be held in either Beijing or Almaty after Oslo pulled out of the race to stage the event last week.
Gandini suggested that Europe's top clubs were concerned that Fifa was rushing into a decision without proper consideration of the ramifications.
"If you were at the meeting at Fifa you felt it was a decision," he continued.
"The impression you have is that 'solution number one' is November/December 2022. It was very important that Europe just put their foot in the door and said 'wait a second, it's going to be very, very difficult for the European leagues', so we want to think about that very clearly."
The taskforce set up by Fifa to decide on the best date for the 2022 World Cup features a variety of stakeholders including clubs, leagues and player representatives, and will meet again in November before a final decision next year.
Sheikh Salman bin Ebrahim Al-Khalifa, president of the Asian Football Federation, has been charged with heading up the task force alongside Fifa secretary-general Jerome Valcke.
Meanwhile, Gandini is the latest official to say he would like the report by former US attorney Michael Garcia into the bidding process for the 2018 and 2022 World Cup tournaments to be published.
Fifa has no plans at present to publish the report but Gandini said: "I'd like to read it, yes."