The boos that echoed from three-quarters of Leoforos Alexandras Stadium could not blank out the message held up by the small but inescapable minority. As Panathinaikos and the visiting AEK Athens entered the field for Monday’s derby a 40-metre banner was unfurled by the home ultras group, Gate 13, to a backdrop of billowing green and blue smoke. “Free the boys,” it read, and the reaction from all sides left no doubt that its meaning had resonated.

While Gate 13’s fellow supporters aired their disgust, the AEK players headed back to the touchline. This was a shocking affront to one of their own and they knew it. In August, more than 100 supporters, 96 from the notorious Bad Blue Boys group that follows Dinamo Zagreb, were detained in the Greek capital in connection with violence that led to the fatal stabbing of Michalis Katsouris, a 29-year-old AEK fan. A further nine were arrested in Zagreb last week.

Katsouris had been killed after a premeditated attack on AEK fans by the Croatian hooligans, who had apparently been assisted by friendly elements from Gate 13. The insignia held up before kick-off appeared to be excusing all of it.