On 24 June 2019, he joined newly promoted side Volos on a season-long loan.
[2] On 23 August 2020, Diamantis signed a four-year contract with OFI on a free transfer.
[4] At the end of the 2022–23 season it was announced that Diamantis would leave the club upon expiration of his contract, having agreed to join an unnamed european team.
In his three seasons with the Cretan based club, he made 79 appearances and scored 3 goals.
[5] On 22 August 2024, Diamantis moved to Iraklis on a one-year contract with an option for an additional season.