During the 2012/13 season, Pavlos Mitropoulos felt he was receiving recognition as AEK had signed him just four months ago and from the very beginning start to gather compliments. Ewald Lienen had an asset, his teammates called him "pit bull", the club was looking to see how it will give €200.000 to Panetolikos to buy him in the summer and the journalists praised by comparing him with Akis Zikos. The 23-year-old midfielder added in the equation players who admires like Kostas Katsouranis, Ieroklis Stoltidis and Claude Makélélé, while he had the feeling that he was unstoppable.It seemed obvious that his career had taken off! As a result, AEK was relegated from the Super League to the Football League for the first time in its history.
In addition, AEK will start their Football League campaign on minus 2 points.
On 7 July 2013 Mitropoulos signed to Panionios as a transfer from Panetolikos. On 13 May 2014, it was announced that Mitropoulos signed a new three-year contract for Panionios, that keep him in the club until 2017, having agreed with the club since January of the same year.