Career
He is a defensive midfielder who plays in the holding midfield role or as an attacking midfielder. Despite often being used in a defensive position he is mainly an attacking player. He has been capped for the Bulgarian national team
Born in Burgas, Yanev started to play football in local club Naftex.
In 2004, he was loaned to Pomorie. In 2005, Yanev returned to Naftex Burgas.
After that the midfielder played for the other club from Burgas –– Chernomorets. Next season in the top division Kosta left excellent impressions in the football specialists with his good play.
In November 2008, the national coach Plamen Markov called Yanev in Bulgaria national football team for a friendly match with Serbia.
On 24 June 2009, Yanev signed a contract for 3 years with CSKA Sofia.