FIFA takes very seriously any allegations of human rights violations related to its events. When it comes to the case you refer to, FIFA has followed up with the Supreme Committee for Delivery & Legacy (SC), who confirmed again that Mercury Mena has never been engaged on a FIFA World Cup construction site under its purview...

the Supreme Committee has engaged several times with the Qatari Ministry of Labour (ADLSA) to discuss the case... We are confident that ADLSA is determined to resolve this matter in an appropriate manner and are pleased to see that ADLSA and Amnesty International are now in close contact to ensure that these workers are fully remedied.