The Sky Blues defender was cited by the Match Review Panel and heavily criticised in some quarters after earning his side a penalty in last weekend’s pulsating 3-3 draw with Melbourne Victory.
Arnold was vocal that the decision was the right one, going on to defend Sydney FC’s culture, but was clear any similar incidents by his players wouldn’t be tolerated.
“It’s exactly what we expected. We saw the footage from different TV angles,” Arnold told reporters at training on Thursday.
“Sebby [Ryall] said he clipped his [Finkler’s] heel and we believe Sebby and the decision has happened exactly as we expected.
“The one thing about Sydney FC is that we try to build a strong culture. I’ve had a harsh word to Sebby about what he did after the penalty to Gui Finkler. I don’t accept that.”
The game threatened to boil over at times, and that’s something Arnold wants to stamp out from his players after other recent melees.
“I haven’t been happy in the last two weeks in ourselves, in Sydney FC. There’s been too many melees in games.
“People turn up to watch the football, they don’t turn up to watch melees.
“It’s something we’ve spoken about in the dressing room and I don’t want to see it again.”
Arnold welcomed having greater selection choicesagainst his former club the Mariners this weekend with two key suspended defenders returning to the selection fold.
“What it does give me is more headaches. We’ve got Nicola Petkovic and Jacques Faty both back from suspension and both fit and ready to play.
“Everyone who played against Melbourne Victory last week did an exceptional job so it gives me more of a headache but it’s a nice headache to have.”
Sydney FC will reprise the away game mentality they trialed for last weekend’s home game by again staying together as a team in a hotel on the eve of Saturday’s clash at Allianz Stadium.
The fifth-placed Sky Blues have failed to win any of their past six home matches but will take confidence from beating Phil Moss’ side in their last two outings, including the 5-1 drubbing in Round 15.
“I expect a really tough contest,” said Arnold. “I know everything about the club up there, all the players and coaching staff and I know they would’ve been hurting a lot after the 5-1 loss.
“We’ve put ourselves in a good spot, we’re travelling well. Our football has been outstanding since Christmas and we’re moving along in the right direction.
“It might be up against my old club and the last fixture there were some personal things that went on against me but that blew up in their face, and this is just a totally different game this weekend.
“I’m still chasing one of the top two positions in the league and I think we’ve got the quality to do that but we’ve got to perform consistently every week.”