So far, he has celebrated nine single and six double victories on the ITF Future Tour . On the ATP Challenger Tour he has won the single tournament in Almaty in 2009 and the single competition in Saransk in 2010 and the double tournament in Samarkand in 2012 . On August 2nd, 2010 he broke through the top 150 in the world rankings for the first time and his highest ranking was a 147th place in August 2010.
Serhejew has played for the Ukrainian Davis Cup team since 2008 . For this he appeared in five encounters, whereby he has a record of 4: 0 in an individual game that was not finished.
Serhejew has not competed in a professional tournament since September 2013 and was last in the world rankings on July 28, 2014.