Arnie fumes in stunning post-match press conference

In extraordinary scenes, Sydney FC coach Graham Arnold stormed out of his post-match press conference following his side's 2-1 loss to Adelaide United on Friday night.

Arriving late and commencing by stating he 'doesn't want to be sitting here', Arnold was fuming at two key decisions which went against the Sky Blues, the first changing the complexion of the contest and the second completely sealing Sydney's fate.

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The visitors were reduced to 10 men in the 28th minute when young star Alex Gersbach was red carded for an ugly - and obvious - studs-up challenge on Adelaide's James Jeggo, which instigated an all-in mid-pitch blue.

Alex Gersbach was shown a straight red card for a challenge on Jimmy Jeggo.

The second and far more contentious call came in stoppage-time when Jacques Faty was whistled for a challenge on Dylan McGowan inside the area, resulting in a 95th-minute penalty strike from Marcelo Carrusca, handing the Red the 2-1 win after Filip Holosko had smartly countered Jeggo's initial strike.

Having already vented during his on-camera interview, Arnold was in no mood to go around again.

"If I could start by saying I don't really want to be sitting here tonight," he said.

"I just want to make a statement and then I'll leave.

"Congratulations to Adelaide for winning the game.

"I'm very proud of my boys, they worked extremely hard.

"(Playing down) 11 against 10, I thought we did exceptionally well and it was criminal how it ended.

"That's pretty much all I've got to say. I would rather you guys write what you saw - you guys write the report how you saw it."

When pressed on what most displeased him, Arnold declined to elaborate other than insisting that McGowan told Sydney players first-hand that he was not touched by Faty in the box.

"It's better that I don't say because last year when I said something, I copped $5000," Arnold said.

"Dylan McGowan said it wasn't a penalty ... he said it to the players.

"That's it."