After that he spent almost five years at Neftochimic Burgas before leaving for Germany to represent MSV Duisburg from 2000 to 2004.

Following that he played for KFC Uerdingen 05 before finishing his active 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.

In summer 2019, Gruev joined Werder Bremen as an assistant coach with a focus on set pieces.

[5] Gruev's son Ilia is also a professional footballer for Leeds United.