[1][2] Born in Istanbul on July 26, 1960, Gülen studied physical education and sports at Marmara University, graduating in 1985.
He was member of Beşiktaş (1980–1981), Sarıyerspor (1982–1983), Sakaryaspor (1986–1987) and Çaykur Rizespor (1987–1989) playing in the Süper Lig..
After one season, he returned home, and became assistant coach to Nevio Scala at Beşiktaş (2000–2001).
Gülen served as assistant to Ziya Doğan at Kombassan Konyaspor (2001) and at Malatyaspor (2001–2002).
Following a season as assistant to Walter Zenga at Gaziantepspor (2006–2007), Gülen became head coach serving at TFF Third League team Yeni Burdur Gençlikspor (2007–2008).