On 27 December 2020, he moved from within Vityaz to fellow Kontinental Hockey League (KHL) club, Avangard Omsk.

[4] During the 2021–22 season while in the VHL with affiliate Omskie Krylia, on 28 February 2022, Miroshnichenko signed a contract extension with Avangard that would have kept him playing in Russia until 2024.

[7] On 1 May 2023, Miroshnichenko left the KHL and signed a three-year, entry-level contract with the Washington Capitals.

Miroshnichenko won the Calder Cup with Washington’s farm team, the Hershey Bears, on June 24, 2024.

[8] Miroshnichenko scored six goals and eight points playing for Russia at the 2021 IIHF World U18 Championships, winning a silver medal.