On 27 November 2019 He gets into a fight with the Etar Veliko Tarnovo's first team player – Ivan Stoyanov during squad training.

[citation needed] In 1999, when he was 19 years old, he was transferred to Levski Sofia,[2] with whom he was Champion of Bulgaria in 1999–00 and won the 2000 Bulgarian Cup.

Kolev made his competitive debut for Levski on 27 October 1999 against FC Iskar in the first round of the Bulgarian Cup, scoring three goals.

In the 2001–02 season, Kolev earned 23 appearances playing in the Bulgarian top division, scoring 18 goals.

In June 2007, Kolev relocated to Germany, signing a contract with TSV Alemannia Aachen.