During his football career, Kushev has often been described as an old fashioned English-style centre forward due to his physical presence and outstanding aerial ability.

In 1996 Kushev was spotted by Spartak Varna, where he scored 6 league goals in his first season and transferred to Slavia Sofia.

After a half season at Litex Lovech, Kushev returned to Russia, signing with Amkar Perm.

On 31 July 2011, Kushev played his farewell game for Slavia, appearing for 10 minutes in the 2:2 draw with Cypriot side Apollon Limassol in an exhibition match.

He played his first and last match for Bulgaria in a 3–0 home win against Luxembourg, coming on as a second-half substitute for Ivelin Popov.