Papadopoulos was sent off in the 75th minute of Brisbane Roar's 3-1 loss to Sydney FC after a tangle with Matt Simon.

The incident was referred to the Video Assistant Referee (VAR) which determined that Papadopoulos had spat in Simon's direction, prompting the latter's reaction.

Simon was also sent off for his retaliation but Bosnich pointed his criticism firmly at the ex-Greece international.

"We know John Aloisi very well as a man and we know he will sort that out but that was disgraceful," Bosnich said on Fox Sports during the post-match.

"Some people are saying on Twitter that the spit didn't hit him, but he went to spit at Simon.

"Simon shouldnt have retaliated but I challenge any man or woman who has been spat at, not to retaliate in any way.

"That is disgusting. We don't need that in our game."

Sasa Ognenovski reiterated Bosnich's stance when discussing the incident.

"You can stare, you can altercations throughout the game, but that's the lowest act you can do on the football field," Ognenovski said.

"For me, you're a centre-half, he's a striker, you want to hurt him, when the ball is there to be won, go through him, do whatever. That's such a low act and no place on the field."

Bosnich added he felt Papadopoulos should cop a six to seven-game suspension.