Sakellariou began his football career in the academy of Panathinaikos, where he stayed for about four years.

At age 17, he left Panathinaikos and turned professional at lower division club Fostiras.

After one season at Fostiras, Sakellariou was signed by Football League (second division) side Ethnikos Asteras.

Sakellariou became a regular at Ethnikos Asteras, and after three seasons his performances were good enough to earn him a transfer to the Super League with Panthrakikos.

In his first season with PAOK, Sakellariou would make 10 Super League appearances, as well as three appearances in the UEFA Europa League, including a 90-minute performance in a 1–0 win over Villarreal and a 90-minute performance in a 1–1 draw with Club Brugge.