On 8 May 2019, he was convicted in court of "intended infliction of minor harm to a health official" and sentenced to imprisonment until late 2019.

In July 2013 Mamayev joined FC Krasnodar on a season long loan from CSKA Moscow.

[12] As a result, Krasnodar announced that they had imposed the maximum fine they could on Mamayev, removed him from first team training and were investigating how to terminate his contract.

[13] Hours before that incident, Mamayev, Kokorin and other young people were involved in an altercation with the driver of a Channel One show presenter; he received brain damage, nose fracture and face contusions after numerous punches.

[1] Considering the time he spent in pre-trial detention, the latest possible date for his release from custody was 13 November 2019.