Ruzhentsev played high school basketball with Hamilton Heights Christian Academy in Chattanooga, Tennessee as a senior.
He averaged 19.3 points and 6.3 rebounds per game, helping lead the team to a 28–3 record.
Also, Ruzhentsev helped Hamilton Heights to three straight NACA national championships.
And in the Basketball League of Serbia, Ruzhentsev became the team's top scorer.
Ruzhentsev was a member of the Russia national under-18 team that took the 6th place at the 2019 FIBA U18 European Championship in Volos, Greece.