Career
Early career and loan Gamakov is youth player of Chernomorets Burgas since 2009. In 2013 he was sent on loan at Neftochimic Burgas till end of season 2013. Chernomorets Burgas After end of season 2012–2013 and his good play at Neftochimic, he returned to Chernomorets.
He made his debut for the team at first match of season 2013-2014 against Cherno more Varna as a substitution.
Botev Plovdiv = 2014-2015 season On 12 July 2014 he signed with one of the top clubs in Bulgarian football Botev Plovdiv. On 13 August 2014 Gamakov scored a goal in the Bulgarian Supercup final but despite his excellent performance Botev Plovdiv was defeated by Ludogorets Razgrad with 1-3.
Milen scored the opening goal in the derby game against Beroe Stara Zagora on 24 October. He was among the best players in the match although he was substituted at the 68 minute.
He played well but received yellow cards in both games.
= 2015-2016 season Foreign Botev Plovdiv season 2015-2016 was marked with a lot of changes of the managers. Despite this Milen Gamakov was regularly included in the starting lineup. In February 2016, due to a lot of injuries of his team mates, Nikolay Kostov started using Gamakov as a central defender.
Under 21 Gamakov scores a goal in the additional time.
Antoni Zdravkov was appointed as manager of the Bulgaria national under-21 football team in October 2014 and he selected Gamakov as the new captain of the team Milen Gamakov missed the game against Wales U21 due to a ban.
He was the captain of the team and played 90 minutes in both games. On 25 March 2016 Gamakov was in the starting lineup as a captain for the goalless draw with Wales U21.
Senior Gamakov was included in the Bulgaria national football team for the first time on 6 November 2014.
He remain and unused substitute during the 1-1 draw with Malta. Club = Neftochimic Burgas = Botev Plovdiv Individual.