Valerianos began playing football with
Olympiacos. He made 44 appearances for the youth team with four goals. Valerianos was first included in Olympiacos' first team in a league match against
Panthrakikos on 11 April 2010, where he appeared as a second-half substitute. On 22 July 2014 he signed for
Iraklis in the
Greek Football League. Valerianos debuted for Iraklis in a
cup match against
Lamia. On 12 August 2015, he signed a contract with second-tier club
Apollon Smyrnis. On 29 January 2016, he solved his contract with the club. On 1 July 2019, after two years with Aris, Valerianos signed a three years' contract with Cypriot club
Pafos for an undisclosed fee. On 4 July 2019, the international back will have an intermediary station in his career after being loaned to
Riga, a Latvian football club, which owns the same property status as
Pafos. According to sources the borrowing will take just a month for the international left back in order to help the club for the
2019–20 UEFA Europa League qualifying phase and play-off round. On 25 June 2021, Valerianos returned to
Greece, signing a two-year contract with
Ionikos. ==International career==