Burnley wore all black, including armbands, in memory of former Northern Ireland forward Jimmy McIlroy who died aged 86 on Monday
A Burnley fan was stabbed before the first leg of their Europa League play-off against Olympiakos in Athens.
The fan was not seriously injured and required stitches to a leg wound.
Three other fans were robbed in Athens city centre before the side's 3-1 defeat and 23 Burnley fans were arrested for being drunk and disorderly. About 1,000 Burnley fans travelled to Greece for the game.
No further details about the incidents have been released.
Burnley, who went into the game unbeaten in their previous four qualifying games under manager Sean Dyche, have not been in European competition since 1966-67.
They beat Turkish side Istanbul Basaksehir and Scottish Premiership runners-up Aberdeen in extra time to set up the tie with Olympiakos.
Source: bbc.com