Early afternoon kickoffs a concern for 2014 World Cup

• Some group-stage kickoff times will be at 1 p.m., where temperatures can be expected in the mid-90s
• FIFA established the kickoff times last week
• FIFA had said it consulted its medical committee before approving the match schedule.

SAO PAULO (AP) — The professional football athletes' union in Brazil is warning that early afternoon matches in tropical cities may jeopardize players' health during the 2014 World Cup.

The union said Tuesday it notified Brazil's Sports Minister Aldo Rebelo and the Brazilian football federation that it is against the kickoff times announced by FIFA last week.

Union president Rinaldo Martorelli told the Associated Press that the body will take all available measures to keep the matches from being held at the hours established by FIFA, including legal action.

"We are sending a message to FIFA to alert them of our concern regarding these issues and saying that we will defend the professional athletes' rights in every level," read the statement of the National Federation of Professional Football Athletes.

The group-stage kickoff times in Natal, Recife and Salvador will be at 1 p.m. local time for two matches at each of the northeast cities.

Those cities can expect temperatures in the mid 30s Celsius (around 90 degrees Fahrenheit) in June.

Martorelli said the union wants to discuss the starting times with FIFA and local World Cup organizers to try to find the best solution possible for the "problem."

"The goal is not to be radical, but to be able to have a discussion with those responsible for the World Cup, so we can make decisions which are positive for everybody," said Martorelli, a former goalkeeper.

Martorelli said that the union is a big supporter of the World Cup but it needs to actively defend the athletes' rights, even when considering "an event of international magnitude."

In addition to the early matches in the tropical cities, the extremely dry weather in the capital of Brasilia is also a concern. The city will host five 1 p.m. matches, including a quarterfinal. In the western Amazon rainforest, Manaus will host two of its four matches at 3 p.m. local time, likely in high humidity.

From the 64 World Cup matches, 24 will be played at 1 p.m. local time.

Messages to Brazil's sports ministry and the local World Cup organizing committee were not immediately answered.

FIFA had said it consulted its medical committee before approving the match schedule.

When asked last week if player's health in Brazil was being jeopardized to please European broadcasters, FIFA secretary general Jerome Valcke said "the health of the player and the quality of the game is on the top of the list before any other consideration, and definitely no commercial consideration."

Kickoff slots in the early stages of the month-long tournament are 1 p.m., 4 p.m. and 7 p.m., meaning the latest matches start at midnight in central Europe.

FIFA President Sepp Blatter recalled that the World Cups of 1970 and 1986 in Mexico scheduled matches at "high noon" in hotter temperatures than Brazil, and at altitude. The 1994 World Cup in the United States also featured matches played in high temperatures and fierce humidity.

"The players' performance is jeopardized," physiologist Turibio Leite de Barros recently told the Folha de S. Paulo newspaper, Brazil's largest. "The U.S. World Cup was one of the worst of all time technically because of the inadequate starting times."

The 2014 World Cup match schedule had already been the subject of debate after Brazilian football leaders and politicians overruled Valcke's original wish to stage matches in four regional clusters to minimize travel in the continent-sized country.