Linfield manager David Healy says the board are “at their wits’ end” after the club were fined 12,000 euro for spectator misconduct in Champions League qualifying against Shelbourne.
On Thursday, Linfield were fined 10,000 euro (£8,727) for “racist and/or discriminatory behaviour of its supporters” and 2,000 euro (£1,745) by Uefa for the lighting of fireworks in Windsor Park during the second leg on 16 July.
The Irish Premiership champions were also handed a partial stadium ban in Europe, suspended for two years.
Healy said a “very small minority” had “let the club down”, and emphasised the vast majority of supporters make up “a brilliant fan base”.
“I know the chairman and the board are at their wits’ end at times with how we can control someone who is going to come into a football ground and say, sing or throw whatever, when it’s basically been put to them that it’s costing the football club,” Healy told BBC Sport NI.
“It’s costing the players and it’s costing us the opportunity of potentially building up a few pound in the pot.
“I would urge supporters to get behind us in the correct way and the Linfield way, like they have done for 140 years.”
Linfield are back in European action on Thursday when they host Zalgiris in the second leg of Uefa Conference League qualifying.
The reverse fixture in Lithuania finished goalless and the winners of the tie will face Vikingur from Iceland in the third round.
“I’ve been here long enough to understand the importance financially to this football club,” Healy said on the tie.
“I think we worked them out pretty well. They changed their shape and we got a good look at them.
“I’m excited by the challenge on Thursday and for the players to go and play well and perform.
“Hopefully we can try and progress.”
