The Danish Football Association (DBU) says it is "regrettable" that FIFA have rejected their request to train with shirts emblazoned with the phrase "human rights for all" at the World Cup.
Denmark revealed in September toned down Hummel kits for their World Cup jerseys, including a third black kit, as a protest to Qatar's human rights record.
The DBU have been proactive in their criticism of Qatar's treatment of foreign workers and restrictive social laws, minimizing commercial activities in the nation while stating last year that training kit sponsors would make way for messages.
DBU chief executive Jakob Jensen revealed on Thursday that FIFA had turned down their training shirts submission.
"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," Jensen told Ritzau news agency.
"We believe the message "human rights for all" is universal and not a political call, but something everyone can support."
FIFA's rules stipulate that any team equipment cannot have political, religious or personal slogans, statements or images, while the organization wrote to teams recently to urge them to focus on football in Qatar rather than ideological or political issues.
Players from Australia, who are in Denmark's group along with France and Tunisia, recently released a video criticizing the human rights record of Qatar, specifically migrant workers and LGBTQ+ people.