Scientific researches on the legal regulations of the fight against doping are carried out mainly in the Western doctrine within the framework of International law, Sports law, human rights, and European Union law. In post-Soviet legal science there is an intensive growth in the number of sports research, mainly sectoral (administrative, constitutional, labor, criminal law). However, there is practically no research on FIFA Anti-Doping Regulations. There is a difference between the two forms of anti-doping rule violation: the first form is the presence of a prohibited substance in an athlete’s sample, the second form is the use of a prohibited substance by an athlete. In this study, we will analyze the practice of the Court of Arbitration for Sport (hereinafter – CAS, arbitration) in cases of anti-doping regulation violations on issues of fault or negligence in football and draw conclusions, what facts can be accepted by the arbitration.