In 2003–04, Pappas' ten goals were a major factor in Kalamaria's winning promotion to the Alpha Ethniki.

Three of these goals came in away matches, where Kalamaria earned crucial points and ultimately prevailed in their battle against relegation.

That season, he scored his first goal for his country in the UEFA European U21 Championship qualifier against Albania in March 2005.

[citation needed] Olympiacos signed him to a five-year deal and immediately loaned him back to Kalamaria for one season.

After a mediocre season, Pappas joined fellow Super League Greece team Skoda Xanthi on 6 July 2008.