Career
He is the current manager of MSV Duisburg. Gruev has played for Levski, Lokomotiv Sofia and Montana. After that he moved to Neftochimic Burgas where he played for almost 5 years, before going in Germany to represent MSV Duisburg from 2000 to 2004.
After that he played for Kentucky Fried Chicken Uerdingen 05 before finishing his playing career in Rot-Weiß Erfurt.
Gruev has 13 caps for Bulgaria, scoring once – on 11 October 1997, in the 2–4 away loss in a 1998 World Cup qualifier against Russia. International goal
Scores and results list Bulgaria"s goal tally first.
Assistant manager
He was assistant coach in Chernomorets Burgas, Hajduk Split, Duisburg, 1. Football Club Kaiserslautern and Bulgaria.
MSV Duisburg
After MSV Duisburg"s bad results and following the release of their manager Gino Lettieri, Gruev was announced as the new manager of the team, signing a contract until 2017, becoming a first team manager for the first time.