Kozlov made his professional debut in the Russian First Division in 2007 for FC KAMAZ Naberezhnye Chelny.

[1] On 24 June 2019, he left FC Dynamo Moscow after 5.5 seasons upon the expiration of his contract.

[3] On 9 July 2021, he joined Nizhny Novgorod, newly promoted into the Russian Premier League.

[4] On 7 June 2013, Kozlov made his debut appearance for Russian national team under manager Fabio Capello in World Cup qualification away game versus Portugal (0-1).

He entered the pitch on 31 min when starting right-back Aleksandr Anyukov picked up an injury.