He played as defender in Trabzonspor (and later coached the same club), Galatasaray SK, and the Turkey national football team.
Sümer was born in Trabzon and started to play football in his home town's club of Trabzonspor.
During this time, he earned the nickname "Deve" (literally: "Camel") due to his tallness and stubborn rough playing temperament.
After having ended his active sports life, Sümer served as an instructor for a while at the Turkish Football Federation (TFF).
[2] He resigned from this post on 5 September 2003 in protest against a resolution made by the Ombudsman Board of the TFF that lifted a ban against Fenerbahçe SK concluded before.