Vellidis played his first of the season on 2 October 2011 against Skoda Xanthi in Kleanthis Vikelidis, giving a fine performance, with having a clean sheet.
Being active for almost five years in the Superleague Greece, Vellidis could be a valuable asset for any club, therefore as Balazs Megyeri's contract expires in summer and it probably will not be renewed, Olympiacos are already looking for his replacement and the Greek player is one of the candidates.
during the last seasons, and in any case, the 28-year-old keeper cashed his offer with a new three-year contract for an undisclosed fee which will tie him with the club till 2018.
[4][5] He started the 2015–16 season being the MVP of the 2nd day of the Superleague Greece in a victorious 3–1 home win against PAOK, as the keeper of PAS Giannina kept upright team with fantastic chips after the first half-hour, when his opponent pushed too much and lost significant opportunities for the equalizer.
From the 30th minute until the end of the half the Greek international showed superb reactions to shots from Róbert Mak, Erik Sabo and Marin Leovac.
On 28 June 2017, he officially included in the roster of his ex-club PAS Giannina, but he was never the same, and after some poor appearances, he was replaced by second choice goalie, Neofytos Michael.
[13] On 19 June 2019, he officially included in the roster of Superleague Greece club Lamia signing a two years' contract for an undisclosed fee.
[14] On 6 November 2019, the serial of the international goalie with Lamia came to an end in a joint consent, on the occasion of the away game against champions PAOK.
[17] On 10 August 2012 Greece head coach Fernando Santos announced the first call up of Vellidis for the friendly match against Norway.