Career
With Natalia Mikhailova, he is the 2006 World Junior silver medalist. Sergeev competed with Natalia Mikhailova on the International Skating Union Junior Grand Prix circuit for six seasons beginning in 2000. They changed coaches in September 2006, moving from Ksenia Rumiantseva and Petr Durnev to Alexander Zhulin.
Mikhailova and Sergeev parted ways at the end of the 2006-2007 season – Sergeev had sustained a number of injuries, including rupture of the outer ligaments of the ankle and a fracture, followed by a meniscus problem after he returned to the ice.
Mikhailova and Sergeev teamed up again in 2008 but they retired from competition after finishing 6th at the 2009 Russian Championships.