The Danish Football Association (DBU) said on Thursday that FIFA had rejected Denmark's request to train at the World Cup in shirts with the words "human rights for all" on them.
The DBU said in 2021 that their two training kit sponsors would make way for messages critical of Qatar while also minimising the number of trips to the country to avoid commercial activities promoting the World Cup hosts' events.
Qatar has come under intense pressure over its treatment of foreign workers and restrictive social laws, leading many participating teams to raise concerns. The country has denied claims that workers were exploited.
"We have today got a message from FIFA that the training shirts our players were to train in, where it would say 'human rights for all' at the stomach [of the shirt], have been rejected due to technical reasons, which is regrettable," DBU chief executive Jakob Jensen told Ritzau news agency.
FIFA declined to comment. Its rules stipulate that any team equipment must not have any political, religious or personal slogans, statements or images.
"We believe the message "human rights for all" is universal and not a political call, but something everyone can support," Jensen said.
FIFA wrote to World Cup teams this month urging them to focus on soccer in Qatar and not let the sport be dragged into ideological or political issues.
Kit manufacturer Hummel said in September it had toned down the details on Denmark's World Cup jerseys and released a black kit as a protest against Qatar's human rights record ahead of the tournament.
Denmark play their first game of the World Cup against Tunisia in Group D on Nov. 22.