2007-08: Sergei Gayduchenko spent the majority of the season with Lomotiv Yaroslavl's second team and made his Russian Super League debut in 11 games with Metallurg Novokuznetsk and was 3-3 with a 3.04 GAA.
2008-09: Gayduchenko appeared in three games with Lokomotiv Yaroslavl in the KHL with a 1.62 GAA and .942 save percentage. Gayduchenko played with Russia in the Canada-Russia Junior Challenge prior to the WJC but was not on the roster for the tournament.
2009-10: Gayduchenko saw limited action in his second year with Lokomotiv Yaroslavl. Playing behind veteran netminder Georgi Gelashvili, Gayduchenko got an opportunity to play late in the season due to a hand injury to Gelashvili but had mixed success. Gayduchenko finished with a 2.42 GAA and .922 save percentage in 20 games.
2010-11: Gayduchenko split the season between CSKA Moscow (Red Army) and the CSKA Junior team in the MHL (U-22 league). In his first season with CSKA after spending two seasons with Yaroslavl Lokomotiv, Gayduchenko shared the goaltending duties with one-time New York Rangers' backup Steve Valiquette. He played in 23 games with a 2.90 GAA and .893 save percentage as CSKA finished last in the KHL's Bobrov Division. The junior team was much more successful – capturing the MHL's Central Division in the regular season and the playoff championship – and Gayduchenko played a big part in that success. He played seven games with the junior team during the regular season and had 1 shutout with a 3.80 GAA and .898 save percentage. In 15 MHL playoff games he had a pair of shutouts with a 1.93 GAA and .927 save percentage.
2011-12: Gayduchenko appeared in 13 games as a backup to Slovakian veteran Rastislav Stana in his second season with CSKA Moscow. Gayduchenko was 2-10, with four of the losses coming in overtime, and had a 2.89 goals against and .904 save percentage. He made two appearances in CSKA's five-game KHL playoff series with Bobrov Division regular season champion SKA St. Petersburg and allowed 7 goals in 105 minutes of action; finishing with a 4.01 goals against and .854 save percentage.
2012-13: Gayduchenko spent his fourth season in the KHL playing for Siber Novosibirsk. He appeared in 19 games as a backup to one-time Ottawa prospect Jeff Glass. Gayduchenko was 6-9-2 with 1 shutout and had a 2.40 goals against and .926 save percentage. Novosibirsk finished fourth in the Chernyshev Division and lost to Avangard Omsk in a seven-game quarterfinal playoff series. Gayduchenko played one period in the playoffs; allowing 2 goals on 9 shots.
Gayduchenko's greatest asset is his size, which he uses to fill the net and take away shooting angles. Though his size limits his mobility somewhat, he has quick reflexes and is a well-conditioned athlete. At his best, Gayduchenko has looked spectacular but his play can be sub-par at other times.
Gayduchenko has one year left on his current KHL contract with Sibir Novosibirsk and looks to build off of what was arguably his best professional season thus far. After his contract expires, should he decide to come to North America, he will have a good chance of becoming the starting netminder for San Antonio.