Career
Korolev was selected 12th overall in the 2005 National Basketball Association Draft by the Los Angeles Clippers. Korolev played for CSKA Moscow in the Russian Super League before joining the Clippers. On July 6, 2007, the Clippers offered Korolev a contract to remain with the team but rescinded their offer in September 2007.
He then returned to the Clippers during the preseason on a non-guaranteed contract, but was waived before the season began.
In December 2007, Korolev signed with Dynamo Moscow. In November 2009, Korolev was drafted in the fourth round of the NBDL Draft by the Albuquerque Thunderbirds.
He was traded to the Reno Bighorns on January 19, 2010. On July 26, 2010 he signed a contract with Spanish club Central Bank Granada.
In August 2011 he signed with Lagun Aro GBC. In December 2012, he joined Spartak Saint St. Petersburg.
In October 2014, Korolev signed with the Greek League team Panionios for the 2014-2015 season.